What to make of Yonder Alonso’s curious 2017

One of the many famous adages about baseball is that it’s a game of adjustments. It’s also a game of inches. And runs, though not in the way basketball is. That one is more literal. Yes, more than anything, baseball is a game of adages. Let’s focus on that first one I mentioned, about the adjustments, and how it relates to new Cleveland Indians first baseman Yonder Alonso.

Long a dead average hitter, 2017 was Alonso’s breakout season as he hit for power at an elite rate with the 17th highest isolated slugging (.287) and 21st highest wRC+ (146) in baseball. He fell back to earth in the second half with a 113 wRC+. How should we look at this?

Logic would dictate pitchers caught on that Alonso was a different animal in 2017 and tried to mitigate damage, hunting for new weaknesses. That can take time to find, though, and Alonso did say he was having a bit of a timing issue at one point in the middle of the season, remarking to FanGraphs’ Eno Sarris, “Pitches I was hitting right I’m just missing — Late, early, just missed the ball.”

Before he trailed off, he added something interesting: “I’ve been hitting a lot more foul balls.”

This could stem from pitchers simply not treating him quite the same as he’d been in the past, which could catch him out of sync. That quote came from an article on August 7th where he was in a dreadful slump from about June on, logging a 94 wRC+ between June 15th and the publishing from that article.

Then, something changed. From the middle of that month to the end of the season he posted a 139 wRC+. Not quite the incredible first half he had, but still very, very good. Though, if we root into it a bit deeper, it’s not exactly like he reverted perfectly. His fly ball rate, a sky-high 48.1 percent in the first half, was a merely higher than average 39 percent in that late year stretch. It was his line drives that picked up the bulk of the remainder, leaping from 21.2 percent in the first half to 24.4 in that final stretch.

That does look like an adjustment, though, that he got used to something they were doing to him. The offerings to him didn’t change a whole ton, except Alonso saw about five percent more two-seamers in the second half, 15.1 percent of the time rather than 10.9 in the first half according to TexasLeaguers.com.

It seemed to have messed with him some:

It seems a little hard to believe one pitch could do that, but pitchers could have been showing him two-seamers at times when in the past he saw four-seams, hence the higher swing rate and whiff rate. If the sequences he was seeing were that different he could have quite a hard time.

If we parse that second half, from the break through August 15, Alonso was fouling two-seamer/sinkers off 32.6 percent of the time. That number slid to 21.5 percent after the 15th. This dovetails with Alonso’s own feeling that he was fouling too many balls off that he’d normally miss, and he figured it out after about a month. Now, we’re swimming in a somewhat small sample size pool here, but a month and a half paints at least a sketch of an adjustment.

He crushed fastballs all year (202 wRC+ against four-seamers) and saw them more than any pitch. It’s possible pitchers saw this, knew this, and began throwing a very similar looking pitch to fastball hunters, but one that is often a bit slower and has enough movement to get off the sweet part of the bat. That small difference could be what threw Alonso all out of wack for a month or so. His foul rate on four-seamers rose also, four points to 21.98 percent. But aside from the two-seam the only pitch that had a demonstrative slide in being fouled off in the second half were change-ups, from 35 percent from the break to August 15, and 17.4 percent afterward.

Alonso’s whole plan for 2017 was to attack baseballs more savagely and hit them in the air. It worked for half a season, until pitchers started using deception and small changes in movement and velocity to fool him rather than big breaking balls (he saw four percent fewer curves in the second half) and he was caught in between for a while. His plate discipline held true throughout the year though.

Actually, it’s a little amazing how little his walk rate and strikeout rates fluctuated throughout the season:

It’s at least heartening to know he didn’t expand his zone or lose his eye even as things stopped going his way.

An OPS in excess of 1.000 is unlikely, but there’s strong evidence Alonso caught on to the off-speed and whatnot pitchers were trying to catch him with. Whether the fly balls return, that’s another story. But with a whole extra offseason focusing on keeping that elevation in his swing and that adjustment made in August, there’s good reason to believe last season was no fluke.