What Does MLB 13 The Show Need to do Next Year to Satisfy Your Baseball Gaming Needs?

1. Fast and young-old players have a higher peak than the rest of the population.
2. Young-old players peak at age 25, which is one year earlier than the general population.
3. Fast players age extremely well from their peaks at 26 to 31, then they lose on average fewer then five runs over five seasons. Young-old players lose more than 10 runs in the same time span.
4. Players with no plate discipline age similarly to the overall population.

Overall, hitters generally decrease their swing rates during their careers. Younger players almost immediately increase their selectivity. In particular, hitters decrease their number of swings at pitches outside the zone. This aligns with the general idea that hitters become more selective the longer they are in the league. But the selectivity doesn’t increase forever. At about age 33, we begin to see a slight uptick in Swing%. Hitters seem to be swinging more at pitches both in and out of the zone.
Also, the older the hitter, the closer the trend in swing rate and Z-Swing% becomes. That’s largely due to the fact that pitchers appear to throw more pitches in the zone to aging hitters. There is effectively a “mini curve” for Zone% from ages 21 to 28, which happens to align with a hitter’s peak years. After 28, the percent of pitches in the zone increases by 1% through age 34—and almost 3% if they last until age 39. There are probably two things going on here, and it’s hard to parse out. On the one hand, as hitters decline, pitchers might realize they can get away with attacking the zone more often. In fact, we see a negative correlation between wOBA in year one and Zone% in year two (-.39). On the other hand, hitters become more disciplined and offer less frequently at pitches outside the strike zone during the same period—at least until age 33. So part of the effect may simply be that pitchers are forced to come into the zone more often against aging hitters because they are less likely to chase bad pitches.

Some initial thoughts:
— Velocity is a young man’s game. Rather than a parabolic curve of some sort, pitchers generally lose velocity from the beginning. Through age 28, they appear to stay within .5 mph of their peak velocity; but starting at age 29 they have lost about 1 mph with the loss accelerating every year thereafter.
— The loss of velocity is important because we see that pitchers’ abilities to record strikeouts follow a curve similar to the speed of their fastballs. However, the slope of the decline is not as dramatic as the velocity decline. This is perhaps do to a couple factors. First, pitchers are likely to further develop secondary and tertiary pitches as they mature. Many of the best arms in the minors can dominate using mostly their plus-fastball and little in the way of plus- or above-average off-speed stuff. But surviving in the majors requires more than just a plus-fastball — which many pitchers quickly realize. Either they develop additional weapons, or they move on. Second, and somewhat related, pitchers might develop a fastball with additional movement — like a sinker or a cutter — to compensate for the velocity decline. This also could lead to a less steep decline in K/9 and SWG_Strike rate than a pitcher’s velocity decline alone might predict.