Pittsburgh Pirates: Analyzing Mitch Keller’s Results Since His Return

Since returning from Triple-A on August 1st Mitch Keller has pitched more effectively for the Pittsburgh Pirates. Let’s analyzing the results for Keller since his return.

Mitch Keller‘s overall stats with the Pittsburgh Pirates this season do not look pretty. Keller has pitched 93.2 innings in 21 starts, posting a 5.96 ERA, although, his 4.32 FIP paints a prettier picture.

A big factor in the difference between ERA and FIP for Keller is that he has allowed just 10 home runs which comes out to a home run rate of 0.96 HR/9. He’s also struck out over 20% of batters faced.

Control, however, has plagued Keller for much of the season. He has walked 10.3% of batters faced, making the second consecutive season in which is walk rate is over 10%. He has also hit a career worst 6 batters this season.

The early season struggles of Keller led to the Pittsburgh Pirates optioning him to Triple-A Indianapolis in June. At Indianapolis Keller worked out of both the starting rotation and the bullpen as he looked to find himself. While he had up and down results with the Indians he did find his way back to Pittsburgh.

Since returning from Triple-A on August 1st Keller has made 9 starts for the Pittsburgh Pirates. In these 9 starts he has looked like an improved pitcher. Let’s analyze what has gone well, and what hasn’t, for Keller since his return.

Keller has pitched 46.2 innings in his 9 starts since returning from Indy. Keller has posted a 4.86 ERA, 3.68 FIP and he’s allowed just 3 home runs (0.58 HR/9). The only reason Keller’s ERA is ballooned to 4.86 is due to one poor start in which he allowed 7 earned runs in 5.1 innings pitched against the St. Louis Cardinals. Outside of that start Keller has posted a 3.95 ERA while allowing just 18 earned runs.

The most encouraging sign from Keller during these starts has been his improved control. He’s walked just 7.7% of batters faced which is an improvement over his 12.7% walk rate that he posted  before being demoted to Indy.

Improved control is obviously great to see form Keller. This combined with an even lower home run rate have both contributed to the improved results from Keller. One negative, however, has been a decrease in strikeouts. His strikeout rate has dropped form 22.4% pre-demotion to 17.4% since being recalled.

Another red flag, despite overall improved results, has been the contact Keller has been allowing. His 91.5 MPH exit velocity is up from his pre-demotion exit velocity (91.1 MPH), while his 38.2% hard-hit rate is a near 4% increase. While his line drive rate has dropped form 26.4% to 25%, it is still worse than league average.

Allowing hard contact is going to lead to a pitcher allowing more base hit. Simple stuff. Since returning he has allowed 63 hits in his 46.2 innings pitched. Yes, his batting average on balls in play of .403 is 100 points higher than league average and indicates that he is due for some positive progression towards the norm, when you allow has much hard contact as Keller does a high BAbip is likely to follow.

One encouraging sign for Keller that has been there all season are his spin rates. His fastball spin rate is in the 73rd percentile of baseball while his curveball spin rate is in the 72nd percentile of baseball. The stuff is there for Keller but it’s up to him to figure it all out and reach his full potential.

Despite the spin rates on Keller’s pitches his whiff rate is career low 11%. While his 20.3% strikeout rate is not necessarily poor, you would certainly like to see it higher with spin rates that strong. This could stem from the placement of Keller’s pitches. A running fastball should be used up in the zone more which is something that could benefit Keller.

Spring Training will be a vital time for Keller. It is no guarantee that he will be in the rotation for the Pittsburgh Pirates when the 2022 season begins. He will certainly be given every opportunity to crack the rotation, but if he struggles in the spring he could be an odd man out.

Even with improved results since his recall from Triple-A Keller’s future remains up in the air. He continues to allow too much hard contact and his strikeouts have also decreased significantly.