In NASCAR racing, pole position is determined by speed trials held before the actual race. Is pole positioning necessarily the ideal place in a race that lasts for hours and has numerous pit stops? What position from the pole is considered by drivers unwinable? Given the long race, why does pole position make a difference?
It is not a guarantee of a win, but it is strongly correlated with first place and top five finishes. The Link above has the analysis for each starting position for every race in NASCAR history that contained 43 cars (the modern number of cars).
The person with the pole has won just fewer than 80 of those races. The person who started second has won fewer than 60.
However, something fascinating about the full analysis, the most likely result of any top five start is a first place finish.
Without having a full data set to work from it's hard to tell much else (and the pictures of the other datasets are quite small). But it's notable that as you go down in starting position your likely outcomes get more diverse. The tail is very short on the pole position, but it grows as you go down in starting position until it is nearly flat at 20 and an inverse of the #1 graph at #43.
The pole position may actually not make a difference in an of itself though. The pole is won by the top qualifier. That means that they've had the best car on the track through qualifying. So what we have, is the data confirming what qualifying has already told us. That this car is faster than the others. However, the fact that the pole car doesn't win more races shows how many other factor are in play.
In other words, correlation does not imply causation. In fact it's very likely that we're dealing with reverse correlation here, wherein a top five position isn't the result of pole position, but because pole cars are faster/better driven.