
Thurman Munson
Veteran backstop and captain of back-to-back Yankee World Series winners in 1977 and 1978, Munson was 32 in August of 1979 when he used an off day in the schedule to learn how to fly. The plane crashed and he was killed.
By that time, Munson was in his 11th major league season, all of it with the Yankees. He was 32 and had caught 1,423 games. Never a great hitter based on the statistics, he nonetheless had hit 113 home runs with a .292 lifetime batting average and 701 RBIs.
For those reasons, his managers generally batted Munson third in those championship lineups, directly in front of Reggie Jackson.
Baseball-Reference identifies several good comparables to Munson, among them Terry Steinbach, Tim McCarver, and Manny Sanguillen. Using those three, we should be able to construct a reasonable projection for what Munson might have had left.
Munson died about 70 percent of the way through the 1979 season. If we merely extrapolate his actual home run and RBI numbers out through the remainder of that year, his career production climbs to 114 homers and 718 RBIs.
The problem is that our three close comparables produced widely disparate results after age 33. Steinbach, a catcher for the 1980s Oakland Athletics, had by far the most productive late career. Occasionally moving out from behind the plate to first base or DH, he added 80 home runs and 315 RBIs to his post-age 33 totals.
Neither McCarver nor Sanguillen had anything approaching that level of success in their latter years. They averaged just nine home runs and 89 RBIs as post-33 players. That’s not surprising, given the famously grueling nature of playing behind the plate.
Munson’s use arc was far more similar to McCarver’s or Sangulllen’s than to Steinbach. At the time of his death, he had caught 1,277 games. McCarver and Sanguillen caught 1,238 and 1,089 through their age 33 seasons; Steinbach only 800.
It’s more likely, then, that what remained of Munson’s career resembled what McCarver and Sanguillen did in their post-age 33 seasons.
To be generous, put Munson at an additional 15 home runs and 100 RBIs in subsequent seasons and retirement in the early 1980s. Combined with what we project him to have done in what was left of 1979 and you have 129 home runs and 818 RBIs.