Swinging strike % is the number of times a batter will swing and miss. It is could be out of the zone, most likely due to movement, but a swing and miss is a strike no matter where it is thrown. This chart is to illustrate the higher the velocity, the more swinging strikes there are for two reasons. The first reason is the velocity and the second reason is the spin rate. I think it is obvious but the more velocity a ball is thrown with, the less reaction time a hitter has thus the more difficult it is to make contact let alone get hits. The spin rate also increases. The seams on a baseball cut through the air and cause the ball to spin. The more spin rate on high-velocity pitches, the more the ball moves. Let's do the extreme here for comparison. A ball is thrown between 98-100 mph with a 2300-2500 spin rate causing 15% swinging strike % (swing and misses). A ball is thrown 88-90 mph with a 2100-2300 spin rate causing 7% swinging strike %. It is simple really, the harder a pitcher throws, the more swing and misses he gets, thus it is important to keep an eye on velocity changes from season to season. As the pitcher ages, or is injured, his velocity will drop which then we can conclude him to be an easier pitcher to make contact off of thus he is a lesser of a pitcher than he once was. We can take advantage of that in the betting market. It is also similar that if a pitcher gains velocity, he becomes a tougher pitcher to get hits off of and he is thus a better pitcher than he once was. Again, we can capitalize on that in the betting market. Of all the spring training games can give us to be ready for the season, this is it.
It is not easy to find this data. It seems the Catcus League either does not report Stat Cast data but the Grapefruit League in Flordia does. I compile a list of those pitchers daily. I will post them here at least once a week with some findings. So with that said, here is the first list of the 2022 spring training velocity changes in pitchers thus far. Keep in mind, this is after only one outing so no matter the finding, we will want to see the results in a couple of outings to "sure up" our findings.
The green highlighted boxes are results of variances of pitchers with velocity gains from their average velocity in 2021. The red highlighted boxes are those pitchers whose velocity has dropped from 2021. I used 1.5 mph as an outlier. PIT Mitch Keller, who was off an injury in 2021, leads this group so far in gained velocity as he averaged 96.7 mph in his outing. MIN Dylan Bundy leads this group in declining velocity. It should also be stated, that anything under 90mph is a danger zone. As the chart above details, a pitcher cannot get make swings and misses in that range which then means balls in play are magnified! These are pitchers we want to find. They are going to get hit often and usually with solid contact. These are "go against" pitchers in every way. Dylan Bundy leads with velocity drop and he is smack in the middle of the danger zone. A prime bet against pitcher! We need to validate his next outing or two, but this is exactly what we are looking for!