Is Something Up With Brandon Belt?

Brandon Belt is one of the most polarizing players in baseball. Even among his own team’s fans, support for the Giants first baseman ranges from ecstatic enthusiasm to downright disdain.

Belt personifies the chasm between old-school and new-school baseball analysis. According to more traditional numbers, Belt leaves something to be desired (at least so far in his career).

He’s never knocked in more than 68 runs in a season; he’s never eclipsed 18 home runs. His career batting average is an unspectacular .273. Although his naysayers will admit that he’s sharp defensively, he’s never won a Gold Glove.

However, Belt excels in less traditional metrics. His career on-base percentage is a robust .350. He’s slugged .458 despite playing half his games in the expansive and cavernous AT&T Park. Despite not yet winning a Gold Glove, his defensive stats consistently rate at or near the top of the charts. Last year, according to the SABR Defensive Index (which uses data instead of the “eye test” to evaluate defense), Belt was the best first baseman in baseball.

To look closer at Belt’s offensive abilities, we must understand a particularly useful and telling stat. According to FanGraphs, weighted runs created plus (wRC+) “is a rate statistic that attempts to credit a hitter for the value of each outcome (single, double, etc.) rather than treating all hits or times on base equally, while also controlling for park effects and the current run environment. wRC+ is scaled so that league average is 100 and each year and every point above or below 100 is equal to one percentage point better or worse than league average.” That may seem like a mouthful, but it’s critically important to use stats like this in the business of modern baseball talent evaluation.

For his career, Belt’s wRC+ is 128, which, by the definition above, means that he’s been 28% better than the league-average Major League hitter. In some of Belt’s better seasons, he’s compiled elite wRC+ totals: 140 in 2013 and 135 in 2015, and he sits at 140 so far this season.

As the numbers show, Belt has been a very good player ever since he put on a Giants uniform, despite the harsh criticism he still receives from more traditionalist fans and analysts.

One of the biggest (and perhaps most legitimate) criticisms of Belt’s game is that he strikes out a lot. For his career, Belt has struck out in 24% of his plate appearances. While this is a pretty high total, it’s not like he’s the worst in the league, or even the worst among very good players.

Kris Bryant, last year’s unanimous National League Rookie of the Year, has a 29% career strikeout rate. Orioles slugger Chris Davis (whom many Giants fans on social media wanted the Giants to sign this off-season) strikes out 31% of the time. Tigers star outfielder J.D. Martinez racked up five wins above replacement last year, and he struck out 27% of the time.

The point is, even the biggest and most legitimate knocks against Belt can be argued against.

And wait a minute. This year, the criticism doesn’t even apply. Brandon Belt isn’t really striking out anymore. Through 92 plate appearances, he’s struck out just 14% of the time.

You may be thinking:

Sure, Belt’s strikeout rate is low so far this year, but he hasn’t even had 100 plate appearances. Surely this is a mirage caused by a small sample size.

In most cases, this is the correct point. However, according to FanGraphs, a hitter’s strikeout rate is actually the fastest element of his game to stabilize (i.e. not fall victim to small sample size). FanGraphs says that is takes just 60 plate appearances for a hitter’s strikeout rate to stabilize.

Let’s take a closer look at Belt’s 92 plate appearances to see how they differ from his career norm.

For his career, Belt has swung at 30% of pitches outside of the strike zone. This year, he’s only swung at 24% of such pitches.

For his career, Belt has made contact with 61% of pitches he’s swung at that are outside of the strike zone. This year, he’s made contact with 67% of such pitches.

For his career, Belt has made contact on 76% of his swings. This year, he’s made contact on 81% of his swings.

The biggest difference appears to be twofold: he’s chasing less and making more contact when he does chase.

One explanation could be that Belt has simply started the year with one of his patented hot streaks. He’s been known to have excellent months, and he’s been known to have miserable months. But even in some of Belt’s best months his strikeout rate has remained around his career average. In May 2015, Belt batted .339/.405/.670 in 121 PA. His strikeout rate for the month was 25%. In August 2015, Belt batted .312/.395/.560 in 124 PA. His strikeout rate for the month was 27%.

Belt has had a few months where his strikeout rate was down, however. He struck out just 11 times in 95 plate appearances (13%) in August 2012. His strikeout rate was 21% in May 2013 and 19% in June 2013, but then it ballooned up to 34% in July 2013. The following month, Belt hit .350/.421/.630 in 114 plate appearances and his strikeout rate was just 16%.

So we have seen some variance in Belt’s monthly strikeout rates, but 16% was the lowest strikeout rate he’s had in a month (min. 15 games played) since 2013. This year, with just two more games remaining in the month, Belt is poised to have one of his best ever months in terms of strikeout rate.

This is particularly interesting because April is the first month of the season. Sometimes hitters come into new seasons and introduce new and sustainable levels of production.

Belt may well be onto something, and he could have a year in which we see a sustained dip in strikeout rate. Or he may simply be having a rare month in which he doesn’t strike at least 20% of the time. Only time will tell, but the early season has been particularly intriguing and promising for Belt and his supporters. For now, at least, the critics are silent.