Row 4 includes a couple of three-time winners and another guy who won twice and might have won more if not for personal problems and missing several races in the prime of his career.
Inside Row 4: Helio Castroneves
The popular Brazilian has been the most dominant driver at Indy over the last decade, winning three times (2001-02, 2009) and capturing four poles (2003, 07, 09-10). Castroneves, who has raced for Roger Penske his entire Indy career, started out with a bang, becoming the only driver in history to win the at the Speedway in his first two attempts.
He followed that up by winning his first pole in 2003 and eventually led a race-high 58 laps, but saw his attempt at the first-ever three-peat derailed by teammate Gil De Ferran, who beat Castroneves to the finish by just .2990 seconds, the fourth-closest finish in history.
Castroneves returned from his acquittal on income tax evasion charges to capture both the pole and the race in 2009. He won the pole again last year and held the race lead before pitting for fuel with nine laps to go and yeilding to eventual winner Dario Franchitti.
One of the fastest drivers of his era, Castroneves is also one of the most consistent. He's led the race in seven of his ten starts (231 laps total) and other than when he was eliminated in a crash on Lap 109 in 2006 has completed the race distance on the lead lap every other time, having completed 1,855 of a possible 1,946 laps (95 percent).
Middle row 4: Louis Meyer
Along with Wilbur Shaw, Meyer was one of the Speedway's better drivers in the pre-WWII era. Like Castroneves, Meyer won as a rookie in 1928 (though he had driven 41 laps in relief of Shaw the year before), the followed that up with wins in 1933 and 1936. Driving hard in search of his fourth win in 1939, he was running second to Shaw but crashed on the backstretch with three laps to go, and while he walked away from the wreck announced his retirement from racing.
Meyer's contribution to the 500 goes beyond his stellar performance as a driver. As an engine builder he was part of the Meyer-Drake partnership that for almost two decades built and continued to develop the famous Offenhauser, a motor that won at Indy a total 27 times and between 1950-60 not only powered the winning driver, but captured all three podium positions.
He also started one of the most well-known traditions of drinking milk in Victory Lane. After winning the race in 1933, he asked for and was given a bottle of buttermilk to quench his thirst after over 4 1/2 hours in the car. When he won again three years later and was photographed with the bottle of milk in his hand, a local dairy producer jumped on board as a sponsor and the tradition was born. With the exception of 1947-55 and again in 1993 when Emerson Fittipaldi eschewed the milk for orange juice in a shameless promotion of his own orange plantation, the Indy 500 winner has drank milk (or poured it over his head!) ever since.
Outside row 4: Al Unser Jr.
Unser Jr. has the odd distinction of winning twice (1992, 94) but is still just the third-winningest driver in his own family, with his father Al Sr. posting four wins and his uncle Bobby bringing home three.
In 1989 his epic duel with Fittipaldi ended when the two touched and Unser careened into the wall as the pair battled into Turn 3 on the second to last lap. He finished fourth the next two years before finally breaking through and winning after another late-race fight -- this time with Scott Goodyear -- and winning by .043 seconds, still the closest finish in 500 history. His emotions flowed in Victory Lane and his tearful comment "you just don't know what Indy means" is certainly one for the ages.
He moved on to Penske Racing in 1994 and won his only pole that year. Nearly a lap down to now-teammate Fittipaldi, he took over the lead after Emmo's Turn 4 crash with 17 laps to go to win his second 500.
Unfortunately, that was the high point of Little Al's career. After shockingly failing to make the race in 1995, Unser Jr. didn't compete from 1996-99 due to the IRL-CART split, and after returning to the race in 2000, competed eight more times and never finished better than ninth, and only led a single lap in that span in 2002.
The split, combined with a number of Little Al's personal issues, likely robbed Unser Jr. of the opportunity to tie, or even surpass, his uncle and father. At the height of his career many considered Little Al to be one of the best drivers in the world, but along with Michael Andretti was probably one of the people most affected by the split.