Originally Posted by Alexamateo
Just looking at it from the outside, There were 62 races that year and a driver could run 61 (two of the races were Daytona qualifiers and a driver could only run one). Only two drivers ran 61 races (David Pearson and champion Richard Petty, while Ned Jarrett ran 59. A few more ran at least 50 races, but none of those are drivers you would consider championship threats, so in general, drivers just went out for the biggest races.
However, the factories dictated it and would only run certain drivers in the full schedule.
In 1962 for example Joe Weatherly won the championship, but for 1963, His factory Bud Moore Pontiac team cut back to just major races, so he picked up rides for the other races driving for no less than 9 different owners as he won his second championship. Most couldn't or wouldn't go to such extremes.