The 2014 xBB% Underachievers, AKA: The Upsiders

Along with the xK% formula I devised and updated last year, I also developed an xBB% equation. Unfortunately, it isn’t as good as the expected strikeout rate formula, as our community has really struggled to determine how the various underlying skill metrics should interact to result in an expected walk rate. That said, my version is still the best I’ve seen, so it’s better than nothing. But there are seemingly consistent underperformers and overperformers, so don’t take a pitcher’s xBB% as gospel.

Today I’ll discuss a group of pitchers whose actual walk rates were significantly higher than their xBB% marks. It’s usually the case that these pitchers are throwing a percentage of strikes that is greater than what their walk rates would suggest. So perhaps that walk rate will decline this season.

Carlos Martinez — 6.4% xBB%, 9.3% BB%

At the end of December, I decided that Martinez was likely not on the verge of a major breakout and he would no longer be considered for the title of my favorite sleeper pitcher of the year. It was primarily due to his major platoon splits and inability to retire left-handed batters. When I wrote that article, I hadn’t yet run the xK% and xBB% numbers, so it’s a surprise to see him with such apparent upside.

Given his obviously strong stuff, likely improvement in walk rate and a weakness we could pinpoint, he’s certainly worth taking a chance on late, even in shallower leagues. Sometimes platoon issues just magically disappear and the upside here is immense if that does indeed happen.

Jenrry Mejia — 7.0% xBB%, 9.8% BB%

Mejia has struggled with the free pass, which is odd considering he threw such a high percentage of strikes last season. He has had control issues throughout his minor league career, so a high walk rate is nothing new for him. I just wonder what xBB% is missing that is causing him to issue so many walks when he throws a high rate of strikes. His xK% is also much higher than his actual K%, driven by a high swinging strike and called strike rate. Either he has all kinds of upside or we’re missing something that will cause him to continue to underperform.

Mejia should open the season as the Mets closer, but bidding is likely to be cautious due to Bobby Parnell’s impending return from Tommy John surgery. Personally, I don’t think Parnell should be a threat at all, since he’ll probably be brought along slowly and his control may be off in the early going. Since Mejia will come at a discount in fantasy drafts and could run away with the job, he makes for a great target out of the bottom tier closers.

Andrew Cashner — 3.7% xBB%, 5.7% BB%

Attention David Wiers, please contain your excitement. Wow. That’s the 11 lowest xBB% among starters! This from a pitcher who has greatly struggled with his control at times in the distant past. Somehow, he has become a strike-throwing machine, as his strike percentage ranked eighth in baseball. Unfortunately, along with a sharp improvement in control has come a decline in strikeout rate. While that hasn’t hurt his real baseball performance, it does limit his fantasy upside.

I was proven right when I shared my extreme optimism of Cashner several years ago, but the path he took to that destination was a different one that I, and likely all of you, had foreseen. It will be interesting to see how much his BABIP rises with that atrocious Padres defense behind him. He’s not going to end up on any of my fantasy teams.

Shelby Miller — 7.6% xBB%, 9.6% BB%

You think the Braves performed this type of analysis when they agreed to acquire Miller? His strike percentage has decline each year since his 2012 cup of coffee, and it sat right around the league average this past season. But the league average walk rate is far lower than 9.6%, so he seemingly deserved a better fate. Perhaps more concerning though is his complete loss of strikeout ability. His xK% backs up the decline as well, as hitters have stopped whiffing on his pitches. He’ll come cheaply this year and your hope is that the Braves can fix him. His peripherals better improve in a hurry, because that SIERA mark paints a serious downside picture.