Mac Williamson Might Just Save the Giants
Some kind of cliff is almost certainly coming, but the Giants figure they could still have another run. For 2018 — and, right now, all that matters is 2018 — the Giants ought to be competitive. Far more competitive than they were last summer. You know the criticisms, though. The Giants are old. They might not have enough youth. And they also might not have enough power. That’s something they’ve worked to address, and their actual power is somewhat depressed by their own home ballpark, but recent Giants lineups haven’t instilled much fear. The club has been done no favors by Hunter Pence’s apparent decline.
Just the other day, 27-year-old righty Mac Williamson hit this home run.
On its own, that’s impressive. Righties don’t hit home runs to that area in San Francisco, particularly at night. But if you know anything about Williamson, you know he’s always had power. Every so often, Williamson would run into a ball and obliterate it. The issue, as it frequently is, was consistency. Williamson didn’t do that often enough. How many hitters do that often enough?
So let’s no longer look at this on its own. Since being recalled from the minors, Williamson has started five games. He homered in the first one. He homered in the fourth one. And he homered in the fifth one. Something might be brewing, here. Because Williamson isn’t just a player doing well. He’s a player doing well after overhauling the very core of his game.
Mac Williamson is a swing-changer. He’s a swing-changer similar to other, previous swing-changers — Williamson is someone who could sense that he was stuck. No longer young enough to be a prospect, Williamson could start to see the approaching end of his career. No one who watched a round of batting practice could question his strength, but one could definitely question his ability to tap into it on a regular basis. Some players might stubbornly stay the course. Williamson went in search of help. The help he found might be familiar to you.
After working this winter with the same private hitting instructor who made such a difference with the Dodgers’ Justin Turner, outfielder Mac Williamson has reworked his swing and become a slugging machine in the Cactus League.
That private hitting instructor is Doug Latta. Williamson was apparently inspired to seek him out after observing teammate Tim Federowicz. Latta quickly identified issues he wanted to correct, and if you’ll allow me to just fast-forward for a second, here’s a quote about Williamson I just found in a new article by old friend Eno Sarris:
“You know who he reminded me of? [Justin] Turner,” said Nationals Manager Dave Martinez.
Martinez has watched Williamson homer against his team twice in two games. I’m not sure how much he knows about Williamson’s story, but the Turner comp is telling. That’s the name that immediately came to his head. Now, Justin Turner is not a particularly large man. Mac Williamson, meanwhile, is both a Giant and a giant. But Latta has molded them to look pretty similar. We’ll look at a few visuals later on.
First, a table. Williamson has obviously barely played this year in the majors, but before recently being promoted, he was also tearing up the PCL. So, just for the sake of understanding how much better he’s hit, check out these stupid numbers.
| Year | Level(s) | PA | SLG | K% |
|---|---|---|---|---|
| 2015 | AAA – MLB | 261 | 0.416 | 24% |
| 2016 | AAA – MLB | 353 | 0.466 | 25% |
| 2017 | AAA – MLB | 455 | 0.419 | 27% |
| 2018 | AAA – MLB | 69 | 0.948 | 12% |
The combined slugging percentage is absurd. The combined strikeout rate is absurd. Let’s take these one by one. Here’s what Williamson’s time against advanced competition looks like, in 15-game rolling-average slugging percentages:
Williamson is tapping into his power like never before. Of course it’s a small sample, and of course Williamson won’t finish with a slugging percentage close to four digits, but this is something that would be hard to fluke. Here’s a similar plot, but for strikeout rates:
Williamson has had a few dips in the past, but this is his best-ever combination of power and contact. This doesn’t mean that Williamson is definitely amazing now. These are just positive early signs. If Mac Williamson were indeed the newest successful swing-changer, this is how we’d expect him to perform. He’d look like a different hitter, the way Justin Turner did, and the way J.D. Martinez did. It’s encouraging when initial data supports the process.
As a reminder, Williamson has always been strong. I’ll pull from Baseball Savant, here. Over the brief Statcast era, going back to 2015, more than 600 players have hit at least 100 batted balls. Williamson ranks 13th in the rate of batted balls hit at least 110 miles per hour. He’s between Miguel Sano and Jorge Soler. Williamson has topped out around 116, which is an elite-level exit velocity. The bat speed has always given Williamson a promising foundation. The idea here is for him to make more of it. Williamson can hit the ball harder than even Turner can. Even a modest improvement could be sufficient to turn Williamson into a weapon.
Now for the visuals. Here’s current Mac Williamson, from the front:
And here’s Justin Turner, from the front:
Here’s current Mac Williamson, from the side:
And here’s Justin Turner, from the side:
There are little differences. Turner still has a more aggressive leg kick. Williamson might bring his hands back more than Turner does. But these are inarguably similar swings, that appear to be informed by similar principles. We wouldn’t expect Williamson to look exactly like Turner, given their different bodies and strengths. But Dave Martinez wouldn’t have had to think for very long to come up with a similar swing. Williamson. Turner. It’s all right there. And you can see how Williamson has evolved over time.
Some changes are probably too subtle for regular TV feeds to pick up on. Like, say, any changes in approach. That’s all in the brain! TV can’t see into the brain (yet). But the bigger stuff is clear. Here’s a Williamson homer from later last year:
Here’s a Williamson homer from earlier last year:
Screenshots:
It was during last season — not after it — that Williamson first tried lowering his hands. But there was more to come.
Now Williamson is more upright, with his most aggressive leg kick. This is all something he’s still trying to get dialed in, after so many years of swinging in a different way, but the new swing is bearing fruit. That only promotes it further. When players try to rewire their own muscle memory, old habits frequently return upon encountering times of struggle. Williamson hasn’t struggled. He’s been given ample reason to believe that his new swing might have truly unlocked his considerable offensive potential.
We spend so much time around here trying to identify the newest breakouts. We’re not alone in that regard — new breakouts are interesting. New anythings are interesting. More often than not, I think, we end up looking hasty. Turns out, it’s incredibly hard to perform as an excellent player in the major leagues. As such, no one can say yet that Mac Williamson is in the process of breaking out. There’s a certain threshold of doing enough for long enough, and Williamson has a ways to go. But, look at what we have. We have a clearly, abundantly talented baseball player. We have a new swing that has already yielded overwhelmingly positive dividends. We have a swing coach who’s aided something just like this before. There’s reason enough to pay attention to this story. Mac Williamson might not save the Giants. On the other hand, what if he did? He occupies a position of need, and he’s attempting to break through at precisely the right time. The Giants have needed someone exactly like this. Mac Williamson probably knows it.
Jeff made Lookout Landing a thing, but he does not still write there about the Mariners. He does write here, sometimes about the Mariners, but usually not.





Jeff’s got the best topical cream and I just rub it all over my body.
Can anybody link videos to home runs hit in that part of the yard by a righty? The only home run I can remember was a lefty – Bond’s 756th I believe.
The link does not exist.
I don’t have a link but Bumgarner said the only righty he remembered hitting one out there before was Justin Upton. (And if IIRC Mark Reynolds once hit one out in that area too). That’s about all I can think of though and I’ve been watching Giants games regularly since they moved to AT&T.
He’s got a loopy hitch in his swing in the early-2017 homer as well. Cocks his hands back too late and is rushed getting to the ball. Late-2017 is much more direct and he doesn’t wait until the ball is almost there to cock his hands.
One thing I would worry about (as if there’s much to worry about with a guy who hits the ball 114MPH and strikes out 12% of the time) is his 59% groundball rate in AAA this year after re-working his swing. Maybe he’s still adjusting to it, but that’s one of the worst of his career. Hitting the ball hard is great, but hitting on the ground is not good for a lumbering power hitter with elite exit velo
His swing at present is looking pretty damn level. I’d expect that, over a full season, we’d see a grounder rate somewhere around 45%. This isn’t an uppercut change as much as it’s just a change in other mechanics.
45% for Mac would be an improvement over 59%, but still far from ideal. Would put him more in line for HR totals with Trea Turner, rather than Justin. Without Trea’s speed and defense, that’s not too exciting.
It’s interesting looking at Turner’s 2014 season when he first started with the new swing, and there’s really nothing at all in the batted ball data that’s different from the prior year other than a more evenly distributed Pull/Middle/Oppo spread. GB% pretty much the same, HARD% and MED% both went down, Contact% went down. The only notable difference is the .404 BABIP. The sustainable improvements came a year later in 2015 when he started getting the ball in the air by decreasing his GB% by 12 points in 2015, and then by another 5 points in 2017.
I guess the pertinent question is what will Williamson eventually become due to this swing change? He was basically Kelly Leak at AAA in 2018 so those numbers don’t really tell us much. But as a Giants fan if Williamson can hit .270/.350/.480, 125 wRC+ I would be very happen with that.
“I would be very happen with that.”
As would I–or even just giving the guy a shot to play regularly for the rest of the season. The obvious problem, about which I have a sad suspicion, is what happens when Pence comes off the DL: if the Giants don’t release him, what are the chances Bochy doesn’t keep running him and his .386 OPS / negative WAR out there? I would be much more surprised if Pence sits than if Mac breaks out.
Bochy had no problem sitting down Rowand and starting a nobody in Andres Torres, so I would be surprised if he sat Williamson for Pence once Pence returns. And he digs the long ball too, he’s no dummy, he knows the long ball necessary, hence why he lobbied for Mike Morse before, after managing him in an exhibition trip through Asia, even though Morse was not a good fielder.
The problem is the last time Mac was hitting well as a starter in 2016, he got injured, and was not able to find his bat, either in the minors or majors, until late last season, as injuries held him back in 2017. And he just fell awkwardly into the wall along the foul line, resulting in him missing yesterday’s game. So that is what I would worry about, him keeping himself in the lineup, and how hard it is for him to find that batting stroke whenever he returns from injury.
People are freaking out because Bochy said that Pence would play when he returns. None of these noticed that Bochy would not commit to starting Pence when he returns, saying they will deal with the question when Pence returns. Bochy always plays his players, he likes to keep the bench active. He also knows that Williamson has been hot and cold before. He also saw Pence hit this spring, who injured his thmb on Opening Day and tried to gut that out. I think McCutchen should be more worried about losing starts, though maybe he moves to CF, Pence RF, and Mac LF, AJax hasn’t been hitting either.
And last I would add that Torres also went to a batting tutor, before signing with the Giants, so this is not the Giants first time with a hitter transformed. Bochy knows hitting, research by Jaffe found that hitters improved greatly when joining Bochy teams, so I’m not worried about Mac playing time.
Cutch in CF makes sense if/when Pence returns even if it weakens their defense up the middle; at least until Cutch proves he is too old for that [or not].
How do these more well known private coaches not get signed by a big league club? I can’t imagine the fringe MLB guys who turn to them have that much money to outpay what they could make on salary?
They are too busy hiring Anthony Iapoce types to complicate swings.
I love this! Tweeted this question at Jeff last night, and I’m going to assume w/ extreme vanity that it motivated the blog post /sarcasm
Man, Turner’s hands are just so quiet in his swing. Hard to compare Mac to him…he’s got a really pretty swing. Short, direct to the ball, keeps the back elbow tucked….crazy good.
How do you add minor league data to a player’s graph on this site? I can only create graphs with MLB data on the player pages.
I will be your personal gif-maker if you desire, Jeff. You know where to find me. Would love to see some of these vids side by side.
Keep it up!
Max Kepler. Looks better against lefties. Anything to get excited about? It’s early but he also looks improved.
I normally have a hard time picking up similarities and differences between swings, but Turner and Williamson are clearly doing the same thing and being rewarded for it. Why hasn’t a team snatched up this hitting instructor, like front offices are snatching up Fangraphs writers?