Pod vs Steamer — Stolen Base Upside

Today we continue our comparison of my Pod Projections with Steamer projections. This time I’m going to check in on stolen bases and begin by identifying nine hitters that I’m projecting for a lower PA/SB rate. Stolen bases totals are primarily fueled by three factors — on base percentage (which itself is driven by a variety of components), how often the player attempts a steal once he reaches base, and how successful he is when attempting a theft. With so many moving parts, it’s sometimes very difficult to forecast stolen bases, especially for certain types of players, like the big sluggers who suddenly decide to run (Manny Machado in 2015 and Bryce Harper in 2016).

In an attempt to figure out what’s causing the disconnect between the projections, I have included the Pod and Steamer OBP projections. Obviously, I mentioned additional factors driving stolen bases above, but I’m going to keep things simple. Remember that the lower the PA/SB, the more steals projected, assuming an equal number of plate appearances. The Pod % of Steamer column is just my PA/SB projected divided by Steamer’s. The lower the number, the more bullish I am compared to Steamer, and vice versa. I included only hitters I projected at least 10 steals for.

Boy, Steamer is not a fan of the Brew Crew. Of the nine hitters in the table, three of them are on the Brewers! It’s pretty bizarre though as the team has shown a willingness to run. Christian Yelich is projected for the second worst PA/SB mark of his career, Lorenzo Cain the worst by a fair margin (his current highest PA/SB sits at 31.6 and was set in 2013), and Ryan Braun the worst mark since 2014, and well above his career average. I get that aging plays a significant role in stolen base attempts, but these regression forecasts seem extreme.

What’s even more interesting is that Steamer is forecasting a meaningfully better OBP for Yelich, which means the system is even lower on his stolen base attempts per opportunity. We essentially match on our Cain and Braun OBP expectations (it still amazes me how often I come so close to the computer systems in some categories considering I don’t look at them at all when manually developing them).

Steamer apologizes for attempting to burst the Byron Buxton bubble. I am actually forecasting a worse OBP and yet still project him to steal more bases per plate appearance. I think some of the explanation is the difference in success rate. He succeeded an astounding 97% of the time last season, going 29 for 30 on the bases. No one expects that kind of success again, but Steamer is projecting Buxton to completely lose his basestealing ability by forecasting a drop to just a 70% success rate. WHAT?! I’m at 85%, and even that’s conservative, with both ZiPS and the Fans just above 90%.

Jarrod Dyson just posted the highest PA/SB mark of his career, which makes sense since he just completed his age 32 season and speed is usually a skill of the young. But Steamer thinks that speed will decline rapidly and he’ll set another new career high this season (even with a projected higher OBP!). I’m basically calling for a repeat of last year. The humidor is potentially going to play a role here as its deflationary effects on offense might encourage the team to run more often.

Mike Trout teased us all with down running seasons in 2014 and 2015, but he has fully rebounded and has been in the low-to-mid 20 PA/SB ever since. Steamer is forecasting the good times to end in 2018 though, with the third worst mark of his career. I’m factoring in some age related decline, but not as extreme.

Michael Brantley appears to be a success rate thing, as he has stolen a crazy 50 bases in 53 attempts since 2014 for an absurd 94% success rate. Yet Steamer is projecting just a 69% mark. His performance remains a question mark due to continued injury issues, but he has remained an elite basestealer. The only times over a full season he has been below an 80% success rate was back in 2012 and 2013.

Tommy Pham was one of last year’s biggest surprises. Obviously, projecting him is harder than projecting Trout. So it’s no surprise that our forecasts would differ, but it’s easy to identify the driver of the discrepancy — OBP. I’m just more bullish, primarily due to a lower projected strikeout rate.

Would you be surprised to realize that A.J. Pollock has only played a full season, recording more than 500 plate appearances, once? He simply can’t stay healthy. But he’s always been a good basestealer. Steamer is projecting his highest PA/SB since his first real season in 2013, while I’m still factoring in a bit of 2015 when he posted a super low 11.5 mark. His stolen base attempts could also get a boost thanks to the humidor.