Al Unser Jr. won the 1992 Indianapolis 500 in the closest finish in Indy history. He finished 0.043 seconds ahead of second place Scott Goodyear. Unser’s 92 Galmer/Chevrolet was on display at the Indianapolis Motor Speedway Museum in 2011 (Johnson Collection)

Indianapolis 500 – Closest Finishes

The closest finishes in the history of the Indianapolis 500, in several distinct categories, are summarized below. Due to changes in the way the race has been run over the years, close finishes for the win did not necessarily become prevalent until the 1970s-1980s. The modern way that yellow flag caution periods have been administered has had the most influence on the proliferation of close competition as well as close finishes. To understand the correlation between cautions and margin of victory, some context and background is needed.

The first yellow light caution system was installed at the Speedway in 1936. If an incident occurred on he track (crash, debris, etc.), the yellow lights would come on around the circuit. From 1936 to 1971, drivers were instructed to slow down and hold their positions under yellow. The field was not bunched up behind a pace car. Passing cars and gaining track position was not permitted when the yellow lights were on, and infractions could be grounds for penalties. The Speedway management felt that drivers who were able to build up a large lead under green should not be penalized and lose it if a caution came out and the field were to be bunched up behind a pace car. Additionally, if the incident was minor, sometimes the yellow light condition lasted less than a lap, and the green was back on after only a minute or so once the situation was safe. Generally, officials wanted as much “natural” green flag racing as possible.

One of the PACER light boards, as seen during the 1972 race.

Many drivers and crews found loopholes in the old system. They figured out ways to make up track position under the yellow lights, mostly undetected. From 1972 to 1978, the PACER light number board system was utilized. Similar in concept to the modern Virtual Safety Car (VSC) utilized in Formula One, and the similar “Slow Zones” at Le Mans, a series of number message boards were situated around the track, recording the intervals between the cars. To make things simpler, the intervals were displayed in “units of time”, not exact seconds. The object was to keep the numbers constant around the track. For example, if the caution period began, and a car’s interval was 5 “units” behind the car in front of him, the driver was supposed to maintain 5 units of distance around the track. If the next board he encountered stated 4 units, the driver was going too fast, and needed to slow down a little. If the next board said 6 units, the driver was lagging behind, and needed to speed up slightly. The boards even had three additional small lights on top, which were for “fine-tuning” and represented fractions of a unit. By 1978, all other Indy car races and all other American oval track races utilized a pace car for caution periods, packing up the field with the pace car ahead of the race leader. For safety, most drivers preferred the pack-up rule, conceding it would work for them just as many times as it might work against them. Emergency crews also preferred the pack-up rule, since it would concentrate the race traffic into one pack rather than having cars spread out all over the track. This would allow them to work on cleaning up crashes, debris, etc., with a clear track, and longer time gaps between cars passing through the work zone. After mixed results with the PACER system (and after new ways to “cheat” the system were discovered), USAC adopted the “pack-up” rule, in which the pace car (sometimes known as the safety car) leads the field during yellow flag conditions, beginning in 1979.

For many years, when the winner crossed the finish line, the race was not yet over. Other drivers still on the track were allowed to complete the rest of the race. Until 1963, the policy of the officials was to let as many cars finish the full 500 miles as possible within a reasonable time frame. Some years, it was an even 8, 10, 12, or more, depending upon attrition, and depending upon the closeness of the field. In some early years, drivers were required to complete all 500 miles in order to receive prize money. In early years cars might be running up to an hour or more after the winner finished, but by the 1950s, the additional time was limited to about 15-20 minutes. In those cases, while the winner was in victory lane, cars would still be roaring by on the track, and many spectators would already be heading for the exits. Additional motivation for allowing cars to finish the full 500 was to induct new members into the Champion Spark Plug 100 MPH Club – a prestigious honor which recognized drivers who completed the Indianapolis 500 at an average speed over 100 miles per hour, without relief help.

Wilbur Shaw beat Ralph Hepburn to the finish line by 2.16 seconds in 1937. It would stand as the the closest finish in Indy 500 history until 1982.

In 1964-1970, the race was shown on live closed-circuit television. In order to better accommodate the television audience, the extra time to finish the race was reduced to about five minutes. In 1974, fans stormed the track to greet winner Johnny Rutherford on his cool-down lap, despite the fact that other cars were still racing. Officials had to red-flag the course and decided a policy change was in order. Starting in 1975, the race was to be over once the winner crossed the finish line. The remaining cars were allowed to complete the lap they were on, then be “flagged” to the pits. Rain shortened the race in 1975 and 1976, so both finished under the red flag. Without rain, the 1977 race would end up being the first race finished under the new “flagged” to pits rule.

With the “pack-up” rule, as well as increased levels of competition, by the late 1970s and early 1980s, close finishes were becoming more prevalent. Prior to World War II, margins of victory of a lap or even several laps, were commonplace. Large leads that were built up were not erased if a yellow caution period were to come out. In the 1950s and 1960s, on average the margin of victory was about a half a lap. In 1961, A.J. Foyt beat Eddie Sachs by 8.28 seconds, after Sachs gave up the lead to pit for tires. It was the second-closest finish up to that point. By the 1980s, an increased number of cars were finishing on the lead lap, ostensibly aided by the “pack-up” rule during cautions. This inevitably led to closer finishes, especially if a late yellow bunched up the field and set up a restart with only a handful of laps remaining.

Closest Finishes (2-Car)

Closest finishes all-time at the Indianapolis 500 between the 1st place and 2nd place cars. List encompasses all races in which the margin of victory was less than 1 second. The list includes races that finished under caution (denoted in yellow). However, generally speaking, races that finished under yellow are often omitted in official lists.

Year Winner Margin
Second Place Notes
2012 Dario Franchitti 0.0295 Scott Dixon Under caution
1992 Al Unser Jr. 0.043 Scott Goodyear Unofficially 0.0331 seconds
2020 Takuma Sato 0.0577 Scott Dixon Under caution
2014 Ryan Hunter-Reay 0.0600 Hélio Castroneves
2006 Sam Hornish Jr. 0.0635 Marco Andretti Last lap pass
2023 Josef Newgarden 0.0974 Marcus Ericsson Green & white flag for lap 200
Last lap pass
2015 Juan Pablo Montoya 0.1046 Will Power
2013 Tony Kanaan 0.1159 Carlos Muñoz Under caution
2005 Dan Wheldon 0.1302 Vitor Meira Under caution
2010 Dario Franchitti 0.1536 Dan Wheldon Under caution
2004 Buddy Rice 0.1559 Tony Kanaan Under caution (450 miles due to rain)
1982 Gordon Johncock 0.16 Rick Mears Closest finish at the time
2017 Takuma Sato 0.2011 Hélio Castroneves
2019 Simon Pagenaud 0.2086 Alexander Rossi
2003 Gil de Ferran 0.299 Helio Castroneves
2007 Dario Franchitti 0.3610 Scott Dixon Under caution (415 miles due to rain)
2021 Hélio Castroneves 0.4928 Álex Palou
1997 Arie Luyendyk 0.570 Scott Goodyear Green & white flag for lap 200
1996 Buddy Lazier 0.695 Davy Jones Green & white flag for lap 200

DATA-1 system

The closest finish in Indianapolis 500 history occurred in 1992. Officially, Al Unser Jr. beat second place Scott Goodyear by 0.043 seconds. However, it is understood that the margin is closer than the official record. Unser was driving a Galmer G92 chassis, a car that was commissioned by Galles-Kraco Racing, designed by Alan Merins, and build in Bicestor, England. At the time, multiple teams in Indy car racing had taken initiative to embark on “in-house” chassis programs, with varying levels of success. Goodyear was driving the more conventional “customer chassis”, a 1992 Lola T92/00 chassis.

The original DATA-1 system hardware on display at the Indianapolis Motor Speedway Museum in 2006. The item labeled “H” was one of the trackside receiver modules, and label “G” is one of the in-car transmitter units.
(Johnson Collection)

At the time, USAC was utilizing the Dorian Automatic Timing Apparatus (DATA-1), a computerized scoring system which had been first introduced in 1990. The DATA-1 scoring system consisted of a series of antennas buried in the track pavement. Each car carried a radio transmitter device. Every time a car passed over one of the embedded antennas, it would relay a signal to the mainframe computer, which kept track of its running position and calculated its speed. The system, innovative, versatile, and revolutionary for its time, was said to be accurate to 1/10,000 of a second. It not only could keep track of as many as 40 cars at the start/finish line, but it could also calculate interval times such as trap speeds down the straightaways and through the corners. It was the first time a fully-automated timing and scoring system was employed, after decades of various manual hand scoring methods, semi-automated methods, and serial scoring with simple paper and pencil.

The transponder device was placed in the left sidepod of each race car. This allowed easy access and established a standard location. Though timing and scoring is typically observed when the front of the car (or the front wheels) touch the finish line, housing the transponder in the sidepods (several feet back from the nose) was irrelevant, since it would be relative for all cars. The Galmer chassis, however, did not have room to accommodate the device in the sidepod location. In 1992, Al Unser Jr. and his teammate Danny Sullivan were the only two cars in the field driving a Galmer. USAC officials that year permitted the team to instead install the transponder in the nose of the car as an alternative.

1992 finish
The finish in 1992

When Al Unser Jr. crossed the finish line to win the race, his transponder actuated the scoring antenna when the nose of his car crossed the finish line. That is where his radio transponder was located. But Scott Goodyear’s Lola (which had its transponder in the sidepod), did not register his car crossing the finish line until the sidepod crossed the line. That relative distance created a fraction of a second lag. The timing and scoring system calculated a margin of victory of 0.043 seconds, which went into the record books as the official margin. However, about a month after the race, USAC technical director Mike Devin announced that a more accurate margin of victory of 0.0331 second was calculated, taking into account the lag and the relative speeds of the two cars down the straightaway.

Closest Finishes (Three-car)

Bobby Rahal crosses the finish line ahead of Kevin Cogan and Rick Mears in 1986. It was the closest 1-2-3 finish in Indy 500 history at the time.

The closest finishes all-time at the Indianapolis 500 between the 1st-2nd-3rd place cars. This list only includes races that finished under green flag conditions. As noted, prior to the 1970s, it was not common for three cars to be running 1-2-3 close together on the lead lap at the finish.

In the 1986 race, four cars were running on the lead lap towards the end. The top three had been running closely together for nearly the entire race, a mostly unprecedented situation during that era. A late-race yellow set up a restart with only two laps go. Kevin Cogan led Bobby Rahal and polesitter Rick Mears. Rahal got the jump on the restart, and passed Cogan as they crossed the start/finish line. Rahal pulled away for the victory, while Cogan desperately held off Mears to finish a disappointing second. The three-car margin of 1.881 seconds was by-far the closest 1-2-3 finish in Indy history up to that point.

Previously, among the few races with three cars on the same lap at the finish, the 1962 race saw Leader Cards teammates Rodger Ward and Len Sutton finish 1st-2nd, with Eddie Sachs in third (+19.93 seconds).

Rahal’s mark has since been bettered several times, but still ranks as the 9th-closest such margin.

Year Winner Margin
Second Place Third Place
2014 Ryan Hunter-Reay 0.3171 Hélio Castroneves Marco Andretti
2019 Simon Pagenaud 0.3431 Alexander Rossi Takuma Sato
2023 Josef Newgarden 0.5273 Marcus Ericsson Santino Ferrucci
2017 Takuma Sato 0.5278 Hélio Castroneves Ed Jones
2021 Hélio Castroneves 0.5626 Álex Palou Simon Pagenaud
2015 Juan Pablo Montoya 0.7950 Will Power Charlie Kimball
2006 Sam Hornish Jr. 1.0087 Marco Andretti Michael Andretti
2003 Gil de Ferran 1.2475 Hélio Castroneves Tony Kanaan
1986 Bobby Rahal 1.881 Kevin Cogan Rick Mears

Dataspeed system

The Dataspeed system was used from 1982-1989. The central module is shown here on display at the Indianapolis Motor Speedway Museum in 2006. (Johnson Collection)

The Dataspeed system was utilized for timing and scoring at the Indianapolis Motor Speedway from 1982 to 1989. Created by San Francisco based Dataspeed, Inc. the system included a timing computer with two electric eyes and up to 40 scorer stations. The computer could keep track of laps completed, running order, lap times, and fastest lap of the day. The calculated information could be output to television monitors as well as the track scoreboards. The system employed 33 scoring assistants (one assigned to each car) who carried a specialized clipboard with a dual stopwatch attached to it. Each time the scorer’s assigned car crossed the start/finish line, a button on the clipboard was pressed, and the elapsed time was recorded on a paper card. The clipboards were wired to the central module and the same information would be relayed to the central computer where it was recorded and processed. The hand-written cards established a back-up paper trail, and scorers assigned to the central unit conducted an audit of the data as the race was ongoing and afterwards. The Dataspeed system was said to be accurate to 1/1000th of a second.

In the 1984 race, the Dataspeed system crashed around lap 70. Officials were forced to revert to back-up hand scoring methods for the remainder of the race. Rick Mears won the 1984 race by two laps, so at no time was there much uncertainty as to who was leading the race. However, it took a longer time to produce the official timing reports for some of the other positions.

Closest Multi-Car Finishes

The closest finishes between the winner and various other finishing positions at the Indianapolis 500. The most cars ever to finish the entire 200 laps/500 miles on the lead lap was twenty-two in 2021.

In 2021, a total of thirty cars were running at the finish, a race record. Of those thirty, 22 of the cars were on the lead lap, and eight were running either 1, 2, or 3 laps down at the checkered flag. The 31st place car completed a record 169 laps, and the 32nd place car completed a record 118 laps. It was the first time the 32nd place finisher made it beyond the halfway point of the race. The most laps ever completed by the 33rd place finisher (last place in most years) was 74 in the 1954 race.

Cars Year Winner Margin
Position Driver
2 cars 1992 Al Unser Jr. 0.043 2nd Scott Goodyear
3 cars 2014 Ryan Hunter-Reay 0.3171 3rd Marco Andretti
4 cars 2023 Josef Newgarden 0.7638 4th Alex Palou
5 cars 2023 Josef Newgarden 0.9934 5th Alexander Rossi
6 cars 2023 Josef Newgarden 1.4316 6th Scott Dixon
7 cars 2023 Josef Newgarden 1.5570 7th Takuma Sato
8 cars 2023 Josef Newgarden 1.8855 8th Conor Daly
9 cars 2023 Josef Newgarden 2.2248 9th Colton Herta
10 cars 2023 Josef Newgarden 3.2648 10th Rinus VeeKay
11 cars 2023 Josef Newgarden 3.4223 11th Ryan Hunter-Reay
12 cars 2023 Josef Newgarden 4.0470 12th Callum Ilott
13 cars 2023 Josef Newgarden 4.7432 13th Delvin DeFrancesco
14 cars 2023 Josef Newgarden 5.0045 14th Scott McLaughlin
15 cars 2023 Josef Newgarden 5.4361 15th Helio Castroneves
16 cars 2023 Josef Newgarden 5.7158 16th Tony Kanaan
17 cars 2023  Josef Newgarden 8.9800 17th Marco Andretti
18 cars 2015 Juan Pablo Montoya 12.0431 18th James Jakes
19 cars 2015 Juan Pablo Montoya 12.7328 19th Simona de Silvestro
20 cars 2014 Ryan Hunter-Reay 13.8391 20th Jack Hawksworth
21 cars 2021 Hélio Castroneves 40.8464 21st James Hinchcliffe
22 cars 2021 Hélio Castroneves 41.5762 22nd Ryan Hunter-Reay
23 cars 2021 Hélio Castroneves 1 lap + 6.2217 23rd Dalton Kellet (199 laps)
24 cars 2021 Hélio Castroneves 1 lap +15.9350 24th Max Chilton (199 laps)
25 cars 2021 Hélio Castroneves 1 lap + 21.4109 25th Pietro Fittipaldi (199 laps)
26 cars 2021 Hélio Castroneves 1 lap + 25.3524 26th Sebastien Bourdais (199 laps)
27 cars 2021 Hélio Castroneves 1 lap + 26.1254 27th Felix Rosenqvist (199 laps)
28 cars 2021 Hélio Castroneves 1 lap + 36.9611 28th Ed Jones (199 laps)
29 cars 2021 Hélio Castroneves 2 laps + 21.3441 29th Alexander Rossi (198 laps)
30 cars 2021 Hélio Castroneves 3 laps + 13.8833 30th Will Power (197 laps)
31 cars 2021 Hélio Castroneves -31 laps 31st Simona de Silvestro (169 laps)
32 cars 2021 Hélio Castroneves -82 laps 32nd Graham Rahal (118 laps)
33 cars 1954 Bill Vukovich -126 laps 33rd Bill Homeier (74 laps)

MOV records

Al Unser Jr.’s split-second margin of victory in the 1992 Indianapolis 500 set a record for the closest finish in Indy 500 history which still stands as of 2021. It bested the famous 1982 race in which Gordon Johncock beat Rick Mears by a then-record 0.16 seconds. Prior to that, the closest finish in “500” history had happened in 1937. Wilbur Shaw beat the hard-charging Ralph Hepburn by a mere 2.16 seconds, an almost unheard of margin at the time.

The 1992 Indy 500 was also the closest finish at the time for any race in the history of Indy car racing. It beat the 1986 CART Budweiser/G.I. Joe’s 200, at Portland International Raceway, where Mario Andretti beat Michael Andretti to the finsh line by 0.070 seconds. Unser also set a mark for the closest finish ever for a 500-mile Indy car race. Previously that record was 0.14 seconds (Mario Andretti over Tom Sneva) at the 1984 Michigan 500

3013 Freedom 100
The four-wide finish of 2013 Freedom 100

The record for the closest finish in a 500-mile Indy car race was later beat at the 1999 CART U.S. 500 at Michigan International Speedway. Tony Kanaan beat Juan Pablo Montoya to the line by 0.032 seconds. Whether Al Unser Jr.’s 1992 Indy margin is interpreted as 0.043 seconds or 0.0331 seconds, the Kanaan margin at Michigan was closer. At the CART Budweiser/G.I. Joe’s 200 at Portland in 1997, Mark Blundell, Gil de Ferran, and Raul Boesel came across the finish line three-wide for the closest three-car finish at the time. Blundell’s margin over second place de Ferran was 0.027 seconds, and his margin over third place was 0.055 seconds.

During the decade of the 2000s, the Indy Racing League/IndyCar Series had a succession of very close side-by-side finishes, particularly on the 1.5-mile “cookie-cutter” intermediate ovals. The all-time closest finish in the history of the IRL/IndyCar Series occurred on September 8, 2002. Sam Hornish Jr. edged Al Unser Jr. by 0.0024 seconds at the Delphi Indy 300 at Chicagoland Speedway. Chicagoland Speedway was also the site of the closest finish in the history of the Indy Lights Series (then known as the Indy Pro Series). On September 9, 2007, Logan Gomez beat Alex Lloyd by 0.0005 seconds (approximately 1.65 inches). The Guinness Book of World Records certified the 2007 Chicagoland 100 as the closest margin of victory in an car race.

Al Unser Jr.’s 1992 margin stood as the closest finish in the history of any race on the Indianapolis Motor Speedway oval until 2013. On May 24, 2013 (Carb Day) during the Firestone Freedom 100 for the Indy Lights series, a spectacular four-wide finish shattered the record. Peter Dempsey beat Gabby Chaves by 0.0026 seconds, with Sage Karam, and Carlos Muñoz also side-by-side. First place to fourth place spanned 0.0443 seconds.

The closest finish ever on the Indianapolis Motor Speedway road course occurred in 2002 during the Formula One race. During the 2002 SAP United States Grand Prix, race leader Michael Schumacher slowed down on the final lap to allow his Ferrari teammate Rubens Barrichello to catch up. The cars crossed the finish line side-by-side, seemingly attempting to stage a “dead heat” or a “photo finish” for Scuderia Ferrari. Barrichello nosed just ahead, and won by 0.011 seconds. Afterwards, it was suggested that Schumacher allowed Barrichello to win as payback for a similar team ordered move (in reverse) at Austria earlier that season.

References & Works Cited

The DataSpeed timing and scoring station set up on the “Fruit Stand” near the start/finish line along pit lane in 1985. (Johnson Collection)