Aaron Cook and the Improbable

There are a bunch of things we know to be true about Aaron Cook, or at least things we have no reason to question. Aaron Cook played for the Rockies, and he recently played for the Red Sox. More recently he was signed by the Phillies. He is a man, and he is a man of more than 30 years, and he is a man who grows reddish facial hair when he wants to, and even when he doesn’t. Aaron Cook knows many things about the game of baseball. Last season, Cook posted one of the lowest strikeout rates ever.

Strikeouts, of course, have never been a big part of Aaron Cook’s game — when he’s right, he gets a bunch of grounders. When he’s wrong, he also gets a bunch of grounders, but the overall results of everything are worse. Cook, in 2012, didn’t post the lowest strikeout rate in baseball history. He did post the lowest strikeout rate since the strike, at 4.9% of all batters. There were 411 batters, and 20 of those batters struck out. When Cook was in triple-A in 2012, there were 153 batters, and 16 of those batters struck out, so this was predictable to some extent.

Cook, in 2012, posted a lower strikeout rate than 2005 Kirk Rueter, and 1996 Steve Sparks, and everyone else since 1995, at least with a 50-innings minimum. Our plate-discipline stats go back only to 2002, but no pitcher with the same minimum has allowed a higher rate of contact. If you batted against Aaron Cook in 2012, you probably put the ball in play. I don’t know if Cook was consciously trying to avoid getting strikeouts, but the evidence suggests that he was in on it.

You all probably knew about Cook’s strikeouts before this. When he pitched for Boston, it was kind of a thing. He didn’t get his first strikeout until his third start. He didn’t get his third strikeout until his sixth start. Because Cook generated so few strikeouts, it’s of some interest to investigate the strikeouts he did generate. I remember reading a fun article at Baseball Prospectus about the time Aaron Cook struck out Mike Trout swinging. That was great, but we can find something weirder. Something weirder happened on September 5, when Cook started a game in Seattle against the Mariners. In the bottom of the first, Cook struck out a batter. Weird, but not too weird. In the bottom of the second, Cook struck out a batter. Inching toward weird, but not too weird. In the bottom of the third, Cook struck out the side. All of the strikeouts were swinging. This gives us pause.

All right, so the scientists among you might note that that’s not exactly what happened. Cook faced five batters in the bottom of the third that night, and he struck out three of them, while the other two walked. To truly strike out the side is to strike out all three batters, with nothing else. But all of Cook’s outs in the inning were strikeouts, and that doesn’t not count. It counted to the NESN broadcast, as Cook walked off the field following the final swing. Remarkably, Cook’s achievement was given surprisingly little attention by either broadcast in the aftermath. Perhaps they weren’t aware of the odds. Perhaps they couldn’t conceive of the odds.

Just flatly using Cook’s 2012 strikeout rate, the odds of him striking out three of five batters are 0.11%, or once per 940 trials. This doesn’t touch on the odds of him striking those batters out swinging, and this doesn’t touch on the odds if two of those strikeouts came against lefties (which they did). Last year, Cook made 18 major-league starts. In 16 of them, he recorded fewer strikeouts than he recorded in this one half-inning alone. You expect that there will be extremes and outliers, but those extremes and outliers are always worth investigating. Who were Cook’s victims in the half-inning in question?

The first was Dustin Ackley, and it took seven pitches. The third pitch was cut on and missed. The seventh pitch was also cut on and missed.

Look at the people in the stands, behind Ackley. Pretty much none of them moved. They all understood the improbability of what they’d just seen. They hadn’t seen anything yet.

The second was Trayvon Robinson, and it took five pitches. The fifth pitch was cut on and missed. Robinson immediately followed Ackley in the order, because apparently Trayvon Robinson batted second for the Mariners for a time. Okay!

Robinson had faced Cook earlier, in the bottom of the first. He struck out swinging, on four pitches. Trayvon Robinson is one of three players to strike out two times against Aaron Cook last season. He’s the only one of those three players to strike out two times swinging. Robinson would later ground out softly in the fourth. This was a victory for him.

Kyle Seager walked, and then John Jaso walked too. That brought the third victim, in the person of Jesus Montero. It took four pitches. The second pitch was cut on and missed. The fourth pitch was cut on and missed.

In fairness to Montero, the pitch was perfectly located. In the opposite of fairness to Montero, it was an Aaron Cook delivery in the strike zone. Montero is another one of the three players to strike out against Aaron Cook multiple times. In this particular game, thankfully, he did it only once.

And that’s how Aaron Cook struck out the side last season against the Seattle Mariners. Unjustly, he’d actually lose, as the Red Sox fell 2-1. But at that point the Red Sox might’ve been a worse team than the Mariners were, and it was the Mariners who had suffered the greater indignity. For the Mariners, 2012 was supposed to be all about progress from the building blocks. Here we see Dustin Ackley and Jesus Montero striking out swinging against the guy with the lowest strikeout rate in recent baseball history. There’s deeper significance in everything, and there’s deeper significance in this.

Interestingly, this was the second time that Cook humiliated the Mariners. On June 29, Cook spun a two-hit complete-game shutout. In that shutout he generated a total of zero swinging strikes. Against Aaron Cook, the Mariners had zero success when the put the ball in play. Against Aaron Cook, the Mariners had zero success when they didn’t put the ball in play. September 5 saw Cook reach his season-high in strikeouts and whiffs. He allowed just two runs in six innings. Red Sox fans will be glad to see Aaron Cook gone, and Mariners fans might feel much the same way.

Since 1995, no regular or semi-regular pitcher has struck out a lower percentage of batters than Aaron Cook did in 2012. On September 5, in the bottom of the third inning, 2012 Aaron Cook struck out the side. Don’t say the recent Mariners offenses have been incapable of doing anything. Those offenses have done things.