I have written about velocity changes from year to year and from start to start. We are searching for those pitchers who either gain or lose it. Yesterday I came across a perfect example of how effective this technique is. This data is for John Gant of STL. Several charts are showing below. The first one is SP John Gant velocity changes year over year.
In 2019, he averaged 96.3 mph on his fastball/sinker, and in 2020 he averaged 94.4/93.9. The variance is virtually 2mph. The jump in velocity from his averages from 2016-2018 to 2019 is misleading. He was a starting pitcher in the first part of those years and then a reliever in the latter years. A starter throws more innings thus more pitchers, therefore does not “max effort” every pitch. A reliever throws 20-30 pitches in an outing so max effort on every pitch is normal.
However, he started the spring training game yesterday throwing 79 pitches! He is getting extended or stretched out like a starter. Some interesting data from that start though. Let’s look.
First, let’s notice the velocity since we have been looking there. His average sinker was 90.0 mph. We should be alarmed at how much lower it is from last season (94.4 mph) and how much lower it was compared to his spring so far (93.8mph). The blue coloring indicates the variance in today’s start against his spring averages. We can clearly see he did not have his best stuff as his velocity was down considerably for all of his pitches.
Second, I made another arrow on this chart. It is pointing to a column labeled as CSW%. CSW% is called strikes plus whiffs as a percent to pitches thrown. His total is at the bottom 25. It means of all 79 pitchers thrown 25% of them were called strikes or swings and misses. 25% is not a very high number. We are looking for 36%> and above 40% for a great day. We can see he threw 35 sinkers (44%) of which his CSW was 17%. Again, this means he was not getting called strikes nor swings and misses. This should indicate balls in play and walks, which correlate to runs scored!
As we can see from his box score, he gave up 4 hits, 1 HR, and 2 walks in only 4.2 innings. We need to spot these situations and take advantage of them. At least, be aware there is an issue here and if we can get value against him, we need to look that way. Keep in mind, there are 9 innings to games. STL though trailing 0-2 when Gant came out of the game, ended up winning this game.