It Remains a Game of Constant Home Runs by Jeff Sullivan May 4, 2017 A few minutes ago, I turned on a game between the A’s and the Twins, which is a sentence no one has ever written before. I turned the game on just in time to see Jharel Cotton pitching to Danny Santana. You might not know very much about Danny Santana. In fact, you probably don’t know very much about Danny Santana. That’s okay. Context clues. Relatively speaking, he’s a little dude. Hits a bunch of grounders. Utility player; reserve; Minnesota Twin. Here’s what Santana did: Off the facing of the second deck. Okay. Good one, Danny Santana. You know that, last season, home runs spiraled out of control. It all technically began around the 2015 All-Star break, and I don’t need to go back over this, because it’s been the subject of dozens, if not hundreds, of analytical articles. At this writing, on May 4, 2017, Yonder Alonso is second on the A’s in home runs. The following players all lead their teams in home runs, either in a tie or by themselves: Kevin Pillar Cesar Hernandez Andrew Toles Josh Harrison Marwin Gonzalez Home runs have been hit by home-run hitters. Home runs have been hit by non-home-run hitters, such that they’re turning into home-run hitters. We probably need to adjust our baselines, because, in short, home runs are everywhere. This isn’t a new article. It’s not fresh, I don’t think. It’s just an article updated with the newest data. The home-run spike is continuing. Whatever’s driving it hasn’t yet been phased out of the game. In this plot, you can see league-wide home runs per batted ball, going back to 1954. Sometimes people prefer to look at home runs per batted ball in the air, but it doesn’t matter what you do. The trends are the same. So far this year, the rate stands at 4.5%. That would be the highest rate in the observed window, topping last year, which was the highest rate in the observed window. Although the increase over last year is slim, it’s still +3%, which isn’t nothing. And, importantly, last year’s data point was extreme. Generally, extreme data points subsequently regress. This one has anti-regressed, because, probably, the mean to regress to is shifting. Now, one thing that’s obviously true about 2017 is that it’s far from complete. So why don’t we look at something like the above, except only for April statistics? Home runs this April were up almost 12% over last April. We have an overall sample of 64 Aprils, and this April’s rate of 4.50% stands as the second-highest, behind only April 2000’s 4.53%. In total, we have a sample of 377 individual months, and this April’s homer rate stands as the fifth-highest. It’s way too soon to conclude anything, but I will point out that based on the extremely early May 2017 data, we’re looking at perhaps the biggest homer month ever. It makes sense that May would pick up where April left off. Why wouldn’t it? Nothing is changing. Except air’s getting warmer. It’s not that hitters are hitting dramatically more fly balls. They’re just leaving the yard more often. Oddly, according to Baseball Savant, league-wide exit velocity is slightly down, even when you narrow to only balls hit in the air. Look, I’m not going to solve anything. I can just share with you what I know, and what I know is that the basic numbers are saying. This is an era of rising strikeouts and rising home runs. Unsurprisingly, then, home runs are playing a bigger and bigger role in offensive productivity. Here, you can see what some people refer to as league-wide Guillen Numbers, over the course of the wild-card era. This shows the rate of total runs scored that score on home runs. Between 1995 – 2015, on average, 35% of all runs scored came in on dingers. Last year, that number jumped to 40%; so far this year, the number has jumped to 42%. To try to split things out, here is average runs scored per game, again during the wild-card era. This shows home-run runs per game, and non-home-run runs per game. It’s nothing you wouldn’t expect, but it’s a pretty stark visual display. Right now, in the average game, you’ll see 1.86 runs score on dingers. That number hasn’t been so high since 2000. But you’ll see 2.61 runs score not on dingers. That number hasn’t been lower in these 23 seasons. Compared to 2000, it’s a drop of 19%. The drop here is gradual, so it’s nothing you’d notice if you just took in a single game at the ballpark, but it’s the easiest thing in the world to explain. Pitchers are better than ever. Strikeouts are higher than ever. It’s tougher than ever to string together walks and hits. Offenses increasingly need those home runs to score guys from first and second, to say nothing about situations when the bases are empty. This is how the game has evolved. It’s not like every single player has adopted the same playing style. We’ve still got Ichiro Suzuki and Billy Hamilton and Ben Revere and, today aside, Danny Santana. There are still productive outs and there’s no pervasive lack of throwback fundamentals. Everyone is amazing. But as Dave wrote about several weeks ago, we’re seeing more of the three true outcomes. And if you thought for a second over the offseason that something was going to change, well, nope. Doesn’t look like it. For whatever reason, the ball is still flying. I don’t know why it wouldn’t. 2017 looks like it’s going to look a lot like 2016, if it doesn’t turn into something even more extreme, and I’m not going to tell you how to feel about that. I’m sure you’ve already made up your mind.