Statistical/Mechanical Analysis into Tim Hill (9/20/2023)

Introduction

This will be a fun one! Today we are going to dive deep into the stats of left-handed sidearm pitcher of the San Diego Padres Tim Hill. From Mission Hills, California, Hill is a 6 foot 4 inch tall, 200 pound reliever who was drafted by the Kansas City Royals in the 32nd round of the 2014 June Amateur Draft. Coming from Bacone College in Muskogee, Oklahoma, he has had a mixed career so far, but with his unique arm slot and being a left-handed pitcher has given both the Royals and Padres, the two teams he has played for so far, the value of a quality reliever who can eat up innings and be a specialist against lefties and produce a high amount of ground balls.

Mechanical Analysis

The obvious first impression is "Wow, a side-arm to submarine arm slot lefty!" However, there's more than what meets the eye with Tim Hill's motion and mechanics. In an interview with MLB during Spring Training of the 2021 season, Hill described his delivery as being "more sensitive to timing" as a rotational pitcher. This means that since he is coming from a side arm slot, his arm is coming across his body at a relatively flat plane, meaning he is rotating his body and arm with force until he releases the ball. Whereas most pitchers who are over-the-top are more linear because they are pulling down on the ball, so are more linear to the plate as they stride down the mound. Even in looking at how Hill finishes, his rear leg spins around showcasing the leftover energy on how his body rotated throughout his motion.

In looking at a study done by Tread Athletics done on the differences between arm slots, it can be described that Hill has an arm slot anywhere between 90 and 120 degrees. This angle combined with his reliance on heavy sinkers, well-located four-seam fastballs, and a sweeping slider helps him play into his effectiveness against left-handed batters. Since Hill relies on his fastball and sinker around 90.2% of the time, he is able to generate a ground-ball rate in the 99th percentile of 63.5% (both metrics are from the current 2023 season). Combined with the natural movement and spin from his arm slot, his pitches seemingly dip at the last second, which generates the high ground ball rate and ability to throw off lefty batters with the pitches starting behind them and then moving into the strike zone.

Statistical Analysis

From 2018 to the current 2023 season, Tim Hill has a cumulative 4.16 ERA in 255.1 innings pitched, along with 208 strikeouts to 117 total BB/HBP. What's intriguing about his stats is ground ball (GB %) and fly ball rate (FB %). Over the course of his six Major League seasons so far, he has an average of 58.9% GB %, which is 16.2 percentage points higher than the MLB average of 42.7%. His career average FB % of 15.9% is also lower than the MLB average of 24.6%. This leads to career average ground ball to fly ball ratio (line drives, LD %, included) of 1.51.

(Credit: Baseball Reference)

This is what makes Tim Hill effective as a reliever. His ability to come out of the pen and generate ground balls so that the infield can field the ball cleanly and throw it to first makes it much easier than having a high fly ball rate. Even though Hill has a ERA in the low 4's, his ability to prevent hitters from hitting hard fly balls that could turn into doubles, triples, and home runs makes him invaluable as a reliever, Keeping the ball in the infield with ground balls is key late in the game to prevent a rally of hitters hitting it in the air to the outfield, and ultimately scoring runs.

Also, take a look at Hill's left-handed batter (LHB) versus right-handed batter (RHB) splits:

(Credit: Baseball Reference)

It is evident that Hill has clearly been better against LHB than RHB throughout his career as righties have a .284 batting average against him, compared to the .223 average lefties have. It's also important to note that for batting average for balls put in play (BAbip) lefties have a .265 average, which is .061 percentage points higher than the .326 righties possess. Looking at BAbip takes a better look into only the ground balls, line drives, and fly balls that are hit and see if the baseballs are finding gaps in the field to drop or make it through the infield.

The fact that Tim Hill has historically been better against left-handed batters and produces a high ground ball rate opposed to a low fly ball rate year after year proves to his managers that he is a reliable option that you as the coach know what you're getting. These stats further solidify to bullpen coaches and managers that Hill is a reliable out of the bullpen arm that can generate a ground ball in a situation when the team needs it the most, or face the batting order in a spot where a couple of lefties are coming up in the next few batters

Conclusion

Tim Hill is a unique study in that he is a lefty side-arm pitcher in a sport where right overhead pitchers dominate the ratios of pitchers in the big leagues. However, Hill has been effective in what he is put in the game to do: get left-handed hitters out and produce ground balls. This provides immense value to his team as he fills the strategic role and succeeds at his strengths and the reason why he is on a Major League roster.