One Big Question: Who is the real Drew Pomeranz?

Welcome to Over The Monster’s One Big Question series. For the next 40 (week)days, we will be trying to answer one important question for each player on the Red Sox 40-man roster. The goal is to find one interesting portion of each player’s game to watch for, whether that be in spring training or the early regular season. We’ll be going straight down the list on the team’s roster page, meaning we’ll be going in alphabetical order through each position group, starting with the pitchers. Today, we’re highlighting Drew Pomeranz.

The Question: Who is the real Drew Pomeranz?

For all of the negativity over David Price’s (relatively) poor year throughout the 2016 campaign, I would confidently call Drew Pomeranz the most disliked pitcher on the Red Sox right now. He cost the team Anderson Espinoza — one of the most exciting prospects in all of baseball — and didn’t live up to expectations in his first half-season with the team. Even worse, the team had a chance to reverse the trade and declined. I understand the decision, and probably would’ve made the same one, but it’s understandable that it’s left a bad taste in everyone’s mouth.

What makes things even more frustrating is that Pomeranz was so damn good before the trade. He made the All-Star team! He looked like a completely different pitcher after coming to Boston, and it’s a confounding issue as we look forward to 2017’s rotation. Which Pomeranz are we going to see?

The lefty’s overall numbers on the season still look quite good. He threw a career-high 170-2/3 innings over 30 starts plus one relief appearance.

A few things stand out here. For one, he was clearly worse. Although by pure run prevention he wasn’t bad, they traded for him to be better than literally average. On top of that, his FIP completely fell off the Earth. We’ll get to why that happened in a minute. On the other hand, Baseball Prospectus’ Deserved Run Average saw him as basically the same guy over the two halves of his season. This is my favorite pitching metric, and gives me some confidence, but I also watched him pitch after coming to the Red Sox. There were clearly some issues.

If you’re looking for what changed, it makes sense to start with the obvious. He went from the Padres to the Red Sox. NL West to the AL East. That’s about as drastic a negative change a pitcher can undergo, particularly for a lefty. Park factors should catch most of that, though. There’s also something to be said about the transition just in terms of pressure. Not just the pressure of playing in a city like Boston, which is obviously more intense than San Diego, but also simply the pressure of pitching in a playoff race. It’s not something he’d experienced before, and being tossed right into that can be jarring.

All of that is pure speculation, though. There are real, tangible portions of Pomeranz’s game that changed after coming to Boston. Most of those changes came in terms of quality of contact. His strikeout rate did fall by a small margin, but his walk rate also came down a bit. Overall, his K%-BB% fell by just a couple percentage points, which wouldn’t come close to explaining the difference in performance.

Kim Klement-USA TODAY Sports

The quality of contact issues would, though. The reason the southpaw’s FIP rose so much, for example, was because of a huge increase in home runs. I wrote about those issues earlier in the offseason, so I won’t rehash all of that in this space.

It wasn’t just home runs. His tendency to leave the ball out over the middle of the plate affected his entire game. There’s a reason his BABIP went from .240 with the Padres all the way up to .306 with the Red Sox. Sure, some luck was probably involved with the first half mark, but it doesn’t explain it all. It’s especially confusing since the Red Sox have an above-average defense, particularly in the outfield. When you look at his batted ball profiles, it makes sense. Pomeranz lost three percentage points off his ground ball rate after the trade, and all three percentage points went to his line drive rate. Simply put, balls that would either be outs or singles most of the time were suddenly turning into doubles, triples and home runs. It’s how you go from allowing a .106 ISO with one team and a .215 one with another. Changing parks and leagues doesn’t explain that big of a change.

Besides these broad issues, Pomeranz also started to struggle more with right-handed bats. Obviously, we expect the southpaw to be better against lefties, but if you’re going to make it as a left-handed starter you have to be okay against righties. He was with San Diego, when he limited righties to a .242 wOBA with a 50 percent GB-rate and a 22% K%-BB%. After the trade, however, righties produced a .345 wOBA with a 43 percent GB-rate and a 15% K%-BB%. The good news is Edwin Encarnacion is now out of the division, giving him one fewer frequent right-handed opponent. Unfortunately, Jose Bautista, Manny Machado, Evan Longoria, and many other talented righties still exist.

So, obviously a lot changed for the worse, but there is still some reason for optimism. For one, Pomeranz was dealing with an elbow injury for much of his time year. This offseason, he’s undergone a stem cell procedure that he hopes will fix that problem. Only time will tell if he’s right about that, but it’s a good sign at least.

Beyond that, there is also the fact that Pomeranz is still a very talented pitcher. His time in San Diego was not all luck. There was real skill there, as evidenced by the strong peripherals that went along with his shiny ERA. A few days ago, I wrote about BP’s new control and command metrics, and Pomeranz graded out averagely. What’s odd, though, is that he got better in both areas after coming to Boston. The BP stats team also introduced pitch tunnelling this week. This is a much meatier topic than the control/command section, and is worth reading if you’re interested. Basically, they are trying to measure how much deception a pitcher has, particularly at the point in which a hitter decides whether or not he is going to swing. According to these numbers, Pomeranz had the fourth most break after that decision point. Clayton Kershaw, who’s pretty good, topped that list.

All of that is to say, there is real talent here. Pomeranz is a former top prospect, and he showed over 17 starts that he can put his talent to use in a string of outings. Because of this potential, I’d put him in my rotation. The Red Sox have theoretical safety in their top three slots, and can afford an upside play at the bottom. If Pomeranz proves to be closer to the guy he was in San Diego, Boston has an elite top-four. If he repeats what he did in the second half of last year...well, maybe we can try backsies again?