What Madison Bumgarner’s injury means for Ty Blach and the Giants

For the first time in his career, Giants’ pitcher Madison Bumgarner is headed to the disabled list.

Weirdly enough, Bumgarner’s injury didn’t even come via baseball-related activities. In fact, he was injured on the team’s off-day Thursday going dirt bike riding. According to reports, Bumgarner bruised his ribs and had a Grade 1 or 2 AC sprain in his left shoulder in the accident. Early indications suggest that Bumgarner is expected to miss six to eight weeks, suggesting a mid- to late-June return.

The injury came as such a shock to the team that manager Bruce Bochy decided to address them in a pregame meeting on Friday, leaving players in disbelief.

It’s no secret that Bumgarner is an important part of the Giants, but how much will the four-time All Star’s absence hurt the team? Let’s take a look.

Bumgarner’s impact on the Giants

Since the 2014 season, Bumgarner has been worth a total of 14.9 fWAR over 103 starts, making him worth around 0.14 wins per start that he makes.

If we assume that Bumgarner is going to miss seven weeks — right in the middle of his expected timeframe — and that he makes roughly 1.3 starts per week, Bumgarner is going to miss around nine starts, or potentially between one-third and one-fourth of the total starts that he would make in a total season.

This loss is huge. Keeping the 0.14 wins as a reference point, Bumgarner would be missing out on around 1.3 fWAR. And, while this does not seem like a lot, this is how many wins Bumgarner would produce above the assumed replacement-level starter, which is what a 0.0 fWAR figure represents. But since we know who Bumgarner’s replacement is — 26-year-old lefty Ty Blach — we can try to figure out more precisely how many wins better Bumgarner would be.

There’s just one problem, though: Blach only has 21 ²⁄₃ innings of Major League experience. It frankly would not be fair (or accurate) to judge him on his performance in 10 games at this level.

That’s where projections come in. The rest of season projections for ZiPS and Steamer each view Blach a bit differently, so let’s break both of them down.

ZiPS obviously thinks that Blach will be a mainstay in the Giants’ rotation for the rest of the season, pegging him for 22 starts and 129 innings pitched. On the other hand, Steamer sees less usage, at just nine starts and 77 innings pitched. Interestingly enough, the nine start figure is exactly what I calculated would be needed from Bumgarner’s replacement, so it seems to see him as just a fill-in for the loss.

The innings pitched numbers are one key takeaway. Blach won’t be able to throw nearly as many innings per start as Bumgarner (almost 7), taxing the Giants’ bullpen more frequently. On days Bumgarner pitches, the Giants only need to worry about six or seven outs from the bullpen, and he can almost act as a day of rest for many of their middle relievers.

Blach, on the other hand, may require more bullpen help. Looking at ZiPS’ projections, if we assume Blach to pitch only one inning per relief appearance—thus leaving him with 125 innings pitched over 22 starts—he may only pitch into the fifth or sixth innings, requiring anywhere from nine to twelve outs from the bullpen. Using the same methodology, Steamer also projects Blach to throw between five and six innings per start.

The Giants’ bullpen is by no means the best in the Major Leagues, ranking 11th in fWAR so far this year. But, they’ve also thrown the fewest innings in baseball, a figure that is surely to go up with the loss of Bumgarner, who has made starts of six (twice), seven and eight innings already this year.

A second difference between the two systems lies in Blach’s quality of innings. Steamer projects Blach to provide higher-quality innings than ZiPS does, reflected in lower ERA and FIP numbers, as well as a higher projected fWAR. Both systems at least see a bit of value over replacement, perhaps cushioning the loss of Bumgarner ever so slightly.

Personally, I’m not a fan of either projection for Blach. Why? It’s because he is such a low-strikeout type pitcher, making it hard to keep his ERA and FIP down. He has just a career 13.4 percent strikeout rate, about nine percentage points below the league average. He does do a good job getting ground balls (career 52.5 percent ground ball rate), but he’s not far enough above the league average to excite me.

Plus, depending on which metric you use, the Giants’ team defense is just average at best, and that does not fare well for Blach and his extreme batted ball tendencies.

When it’s all put together, what is the total loss for the Giants? Potentially one to two fWAR and perhaps more based on the bullpen’s increased role. Without a doubt, this could be the difference between making the postseason and fading down the stretch.

Plus, few starters pitch better than Bumgarner in high leverage situations. And, no, I don’t just mean his postseason abilities. Since 2014, just seven starting pitchers have a better xFIP than Bumgarner in the highest leverage situations during the regular season. His ability to be “clutch,” a word sabermetricians don’t like to throw around too often, led to a WPA that ranked among the top-15 starters in baseball.

This does not even take into account Bumgarner’s bat, which can be a nightmare for opposing pitchers. He’s not a free out at the bottom of the Giants’ order, and I’m sure we are all aware; unless Blach has some secret offensive abilities, that could represent another 0.2 or 0.3 WAR lost from Bumgarner’s baseline.

Lastly, there are intangibles Bumgarner offers that Blach won’t. He has experience and leadership. Outside of perhaps Buster Posey, there isn’t any player on the Giants that they’d rather lose for an extended amount of time than Madison Bumgarner. Friends don’t let friends ride dirt bikes.