hit 101 a few times vs us...
It's really crazy, here are the velocity changes from 2016 to 2020 for other guys essentially the same age:
Kershaw- 93.7 to 91.7 (-2 MPH)
Strasburg- 95.9 to 94.3 (-1.6 MPH) (based on 2016 to last year as he hasn't pitched this season)
Maeda- 90.9 to 92.5 (+2.5 MPH) (only increased 0.4 MPH since 2017 though)
Kuechel- 89.2 to 89.0 (-.2 MPH)
Bassitt- 94.1 to 93.9 (-.2 MPH)
Richards- 96.3 to 95.1 (-1.2 MPH)
Duffy- 95.5 to 92.1 (-3.4 MPH)
You could add Minor and Cobb to this group but Minor was a reliever for part of this stretch and Cobb only had 22 IP in 2016 so I didn't include them.
So of this group of similarly aged starters, all but 1 experienced a decline in velocity. Some of the declines were so small as to be insignificant but only one saw any improvement in velocity. The only other person with any significant improvement in velocity was Maeda.
Maeda was a Japanese import whose rookie season was 2016. In 2016, his fastball averaged 90.9 MPH. In 2017 his fastball averaged 92.1 MPH. It's held very steady ever since between 92.1 and 92.5. I think the transition to MLB probably caused the jump in his fastball. Either he started throwing it harder to have better success or more emphasis on strength training helped. But he has seen no real change since that initial jump.
So deGrom is an outlier. I really wonder what the deal is. We see guys go to different teams or spend an offseason at driveline who get a one time boost to their velocity but a steady climb of 5 MPH from age 28 to age 32 is bizarre.