Gio Gonzalez's Emotions Don't Hinder His Pitching, So For the Love of God, Stop Writing About It

And they never have.

Let me explain. It's not hard to find an article about how Gio Gonzalez's amped up emotions caused him to meltdown and spiral out of control in crucial situations when he was younger. Writers keep talking about how his newfound maturation has been partially responsible for his improvement in recent years. Apparently now, unlike before, he's been able to filter out his emotions and focus on getting hitters out when it matters most. Case in point: here, here, and here.

It's all a load of crap.

It's so simple to test this, that I'm amazed that nobody has bothered to put this to rest until now. If it's true that he was wilting under pressure, all we have to do is see if Gio performed worse in high leverage situations than in low leverage ones. A high leverage situation is a game state where the next action has the potential to cause a large change in win expectancy, like bases loaded, two outs, in the bottom of the 9th of a one-run game. Naturally, those high leverage situations are synonymous with high pressure—which is something that has been claimed to cause the mentally unfocused Gio to break down and lose control. Thankfully, there's a stat that measures exactly that—WPA Clutch score. It's normally meant for hitters, but it can easily be applied to pitchers, too. The formula for Clutch score is this:

WPA/pLI - WPA/LI = Clutch

Put simply, all it does is measure a player's performance in a context-independent sense and subtracts that from a context-dependent one. If a player performs better than his season average when it matters more, the Clutch score will be positive. And inversely, if a player performs worse than his usual numbers in important situations, the Clutch score will be negative. The stat is put on a scale of wins where the average is typically 0, and a vast majority of players end up with a Clutch score between +1 and -1 over a full season. So if a player has a Clutch score of +0.50, that means his clutch performance has been worth an extra half win.

So how does Gio fare?

Over his whole career, his total Clutch score is +2.16. And that's the sixteenth highest clutch score among any pitcher in the major leagues, qualified or not, starter or reliever, from 2008 to 2011 combined.

But wait, there's more.

Remember all of that talk about how Gio found out how to focus recently, but he was a head case early on? Aside from his first little two month cup of coffee in 2008 (when he only threw 34 innings), he's been positive every year. Hugely positive, even. And not only that, his Clutch score has been amazingly consistent, year after year, young or old, raw or mature.

All stats are up to date as of 5/7/11. The column headers on the table are, in order:

• Innings pitched.
• pLI: This is the average leverage index of Gio's innings over the whole year, where league average is 1. For a starting pitcher who creates his own messes (as opposed to a relief pitcher, who gets put into them), this essentially measures how much trouble his innings are. A pitcher who consistently gets in a lot of trouble will have a high pLI, whereas a pitcher who cruises to easy victories will have a low one. Note that this is also dependent on other factors, such as offensive support, so it's not a great measure of a pitcher's quality.
  
• Clutch score. The reason the total clutch score isn't just the sum of his four years is that it's a weighted sum—the year with 200 innings is going to count a lot more than the year with 34.
  
• Team Rank: For every year that Gio pitched, I ranked all of Oakland's pitchers in order of Clutch score. And yes, that's right—Gio has led the team in Clutch score for three straight years, and it's not close. Over the four year period, the next closest pitcher to Gio is Trevor Cahill, with a relatively puny 1.07.
  
• League Rank: Same principle as Team Rank, but for the whole league. I'm including every pitcher that ever pitched in that time period, regardless of quantity.
  
• QS League Rank: This is like League Rank, but I'm restricting the list only to qualified starters. According to the MLB rulebook, for a pitcher to qualify (for things like the ERA title and such), a starting pitcher needs to throw 1 inning per team game, which comes out to 162 innings per season. The years with the asterisk show where Gio would have ranked had he qualified, which he didn't. He only qualified for 2010 and 2011 (so far), as he didn't have 162 innings for the other two years (or 648 innings over the four years).
  

I know that Gio and his teammates have talked about how he's learned to keep his emotions in check. I don't doubt that. I also know that Gio looks more animated than other pitchers while he's on the mound. I don't doubt that either. But it doesn't matter what he feels like or how he looks—from our standpoint, all that matters is how it affects his pitching and his results. It doesn't. His emotions didn't affect his pitching then, and they don't affect his pitching now. Over his entire career, Gio's been one of the best in the league at focusing and getting outs when they matter most. It's that simple.

So can we finally put this myth to bed, in the discarded pile of silly psychological theories where it belongs? Please?