Mike Bolsinger’s New Weapon

Best known for inciting a bench-clearing brawl between the Reno Aces and Albuquerque Isotopes last summer, the Los Angeles Dodgers could not have possibly anticipated that Mike Bolsinger would become a permanent fixture in their starting rotation this season. He was the quintessential “break glass in case of emergency” option when the powerhouse baseball operations duo of Andrew Friedman and Farhan Zaidi picked him up from the Arizona Diamondbacks for cash considerations last off season. After losing marquee free agent signee Brandon McCarthy to a torn UCL, which required Tommy John surgery last month, the Dodgers rotation suffered another crushing blow when news leaked out earlier this week that Hyun-Jin Ryu is opting to undergo season ending shoulder surgery. A perfect storm of devastating injuries and Bolsinger’s stellar early season performance (1.42 ERA with a 13.26 K% in 19 innings) at Triple-A have given him, along with Carlos Frias, an opportunity to stick in the rotation permanently.

Obviously the 25-year-old Frias, who held the Giants to one-run over seven innings earlier this week, is the more intriguing fantasy option of the pair, but the 27-year-old Bolsinger will likely cost less in all dynasty leagues to acquire via trade and is widely available on deeper league waiver wires. Bolsinger was atrocious in a brief stint with the Arizona Diamondbacks, going 1-6 with a 5.06 ERA in 10 appearances (nine starts), last season.

Given a new lease on life in Los Angeles, Bolsinger has taken full advantage, posting a 2-0 record with a 1.04 ERA through 17 innings (three starts). Aside from a mammoth home run served up to Giancarlo Stanton (no shame there son), he’s been virtually untouchable. The strikeout rate is actually down for Bolsinger (7.27 K/9) this year, but his walk rate has remained stable (3.12 BB/9). He’s also benefited from a microscopic .261 BABIP and a preposterous 98.6% strand rate, both of which are going to regress in time.

Coming into the season, Bolsinger profiled as an ideal back of the rotation starter in a best-case scenario. He’s made several adjustments to his arsenal, which gives him a realistic chance to reach that ceiling and stick in the Majors long-term. Most notably, he’s added a brand-new slider (throwing it 13% of the time), which now gives him four pitches and may explain his early season success.

Bolsinger Velocity

The slider has quickly evolved into Bolsinger’s best pitch, generating a 17.65 whiff percentage through three starts. According to Harry Pavlidis’ widely cited research on the Hardball Times from 2011, a league-average whiff rate on a slider is around 32 percent. The slider may not be a league-average pitch, but it’s worth noting that he is getting plenty of swings and misses on it.

Bolsinger Whiff Percentage

When you add the slider into the mix, along with his curveball, it gives Bolsinger two weapons (instead of just the one he was working with in the past) to attack opposing hitters.

“It was a pitch that I thought wasn’t going to be as good as it was,” Bolsinger told J.P. Hoornstra of Inside The Dodgers in late April. “Throwing that fastball inside to righties and lefties, it opens up the other side of the plate so much. That’s where that slider compliments that inside pitch. That’s what I’d been most surprised about.”

Another noticeable change for Bolsinger is that he’s improved where he is locating his pitches. He’s done a masterful job working the outside corner against right-handed hitters, while working low and inside against southpaws. Bolsinger lived over the plate last season, he’s doing that a lot less this year, working around the perimeter of the zone instead.

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This development not only explains his early season success, but likely gives some insight into the sharp increase in his ground ball rate, which has spiked into the elite range at 57.8%. It also may explain the dramatic increase in the amount of soft contact he’s generating, which has nearly doubled from 12.7% last year, to 23.4% this season.

Realistically, Bolsinger is never going to be a fantasy superstar. He doesn’t have the raw stuff necessary to become a top of the rotation starter in any universe (real or fantasy) but fantasy owners should acknowledge the legitimate improvements he’s made this season, adding a slider and improving his location. The difference between perennial contenders and also-ran franchises in dynasty leagues often comes down to rotation depth. Given the Dodgers black hole in the starting rotation and Bolsinger’s progress, he could provide plenty of fantasy value down the stretch this summer, and will cost nothing to acquire.

George Bissell also writes for You can follow him on Twitter @GeorgeBissell

The Author

George Bissell

George Bissell


  1. ayzzy
    May 20, 2015 at 11:14 am

    So would Bolsinger compare to someone like Roberto Hernandez right now? With a greater chance for wins, though.

    • May 27, 2015 at 8:19 am

      I would put Bolsinger ahead of Hernandez by a mile. He will always be Fausto Carmona to me tho.

  2. Tim Johnson
    May 21, 2015 at 2:43 pm

    Great article! I have a non-related question about my dynasty team that I was hoping you could help me out with… I’m 18-41-1 this season, good for worst in the league. 2 of my 3 best pitchers are (were) Ryu and Cobb, and all my guys are underperforming pretty severely. I feel like the team should turn it around, but it’s been so horrible so far. Am I just hurting myself by not rebuilding at this point, or is it too early to give in? I just feel at this point, I have no shot at contending (with that record). My starters are C: Sal Perez, 1B: Chris Davis, 2B: Daniel Murphy, 3B: Longoria, SS: Castro, MI: Rollins, CI: Morneau, OF: Calhoun, Choo, Pollock, Leonys Martin, UT: Fowler, Bench: Mauer, Kang, Eaton, Marisnick, and pitchers are: James Shields, Gio Gonzalez, Alex Wood, Jose Quintana, Jared Weaver, R.A. Dickey, Mike Leake, Jason Grilli, Jeurys Familia, Heston, Osuna, A.J. Ramos, Cobb (DL), Ryu (DL), Nova (DL). 12 teams, I feel like I should be doing better but the team is just not getting it done. Thoughts? Thanks in advance!

    • May 27, 2015 at 8:23 am

      I would hang in there for now, you definitely have some pieces. The important thing to remember is that you can go on a run in the second half and still have a shot at the playoffs. I’ve seen it happen plenty of times where a team sells too early. If a month from now you’re still nowhere close to contending, the guys to sell are your closers and older veterans. I’m not getting rid of core guys like Shields, Wood, Perez, Longoria etc…

  3. Sam
    May 29, 2015 at 2:55 pm

    How would you rank Bolsinger against Hector Santiago, Jesse Hahn, and Kyle Gibson?

    • May 31, 2015 at 5:44 pm

      Hey Sam, I would consider all of them essentially replacement level talent. I like Bolsinger the most out of that group because he’s in the NL…Hahn and Gibson are hit or miss most of the time…

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