Measuring "Plate Skills"

One last funky stat: "Hitter's +/-"

Once again, to recap our overall philosophy:  PRODUCTION + PLATE SKILLS + AGE-ARC

We got a new stat to measure "Production," which is called "Plausibility Index," which is covered via the "Allegory of the Window."  I felt there needed to be a stat that incorporated both walks and extra-base hits, but also recognized that strikeouts impact Production by reducing the number of balls in play, and, thereby, increasing the necessary conversion rate (the rate of conversion of balls in play to "random-y singles") to a level that may (if it's very high) make offensive success "implausible."

So what about "Plate Skills," the other part of the formula?

Plate Skills can be measured by on-base percentage, or by "eye ratio" (BB / K), or by separate calculations of K% (K / PA) and BB% (BB / PA).  But, here again, I didn't think we were getting the whole picture.  Just like I view strikeouts as a non-trivial part of Production, I view "hitting the ball with authority" as an integral part of Plate Skills.

In other words, it's not just a matter of distinguishing balls from strikes, it's distinguishing a "hitter's pitch" from a "pitcher's pitch."  The latter two may be balls or strikes, so "just" strike-zone judgment is not enough.  When the hitter gets a "hitter's pitch," what is he supposed to do with it?  Hit it!  So, except as it demonstrates the relative ability to avoid strikeouts (by connecting with the ball), "eye ratio" doesn't really cover that part of Plate Skills.

OBP, then, might be better ... except, (1) it doesn't tell you anything about strikeouts, and (2) it can be  mightily affected by our old friend the "random-y single."  As we've noted, the "random-y single" represents a ball hit without authority, and our system treats "random-y singles" as no better than "random-y ball-in-play outs."  Our theory is that the ability to hit "random-y singles" against minor-league pitching doesn't really tell us anything about a prospects likelihood of major-league success.

So, once again, we devised our own stat, which we dubbed "Hitter's +/-

Without going into excruciating detail (well, maybe we already have), we took what appeared to be a reasonable "average" distribution of our six measurable "plate outcomes" from a bunch of major and minor leagues.  [Again -- going back to the Manifesto -- we weren't looking for a "perfect" model, just something "reasonable."]  [The six are walks, strikeouts, home runs, balls hit with authority (2b + 3b), singles (assumed "random-y" per our assumption), and ball-in-play outs (also assumed "random-y").]

Once we had this "normal distribution" of plate outcomes, there is an "expected" OBP resulting therefrom.  It was .295.  If a hitter's results reflected that "normal distribution," he would have a "Hitters +/-" of 0.00, because he would have neither increased nor decreased his "expected" OBP.

OK (maybe?) ...

We then take each plate appearance and measure the difference between that particular plate outcome and the "expected" OBP.  A strikeout drops that PA's expected OBP from .295 to .000, so each strikeout is weighted at -.295.  A home run or a walk increases the "expected" OBP from .295 to 1.000, so they are weighted at +.705.  Balls in play hit with authority (measured as doubles and triples) we calculated (somewhat arbitrarily) to be worth +.225.

Singles and balls in play hit without authority we assume are neither positive nor negative (but "random-y").  Therefore, they neither increase nor decrease the "expected" OBP.  In other words, they don't count in this equation at all.

So ... for a hitter to achieve a positive "+/-" the value of his weighted XBH + BB must exceed the value of his weighted K.  Singles and ball-in-play outs are assumed out of the equation.  If a hitter achieves that positive value, then he is turning the plate appearance to his advantage vis-a-vis the pitcher. 

That last thing, ultimately, is what we are driving at.  The hitter must "play defense" against the pitcher's attack in order to "play offense" against the other team.  The ability to do that is what this stat is driving at.



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Tacoma Rain's picture

Tacoma Rain

You have not lost me so far... and I do think it makes baseball sense so far from my point of view.


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moethedogthe return to the interesting LoMo: I've written several times before that the most interesting Logan Morrison was the one he was as a rookie. he was an OBP 1B then, not really a slugger. Rookie numbers = .283-.390-.447. The Slg% was inflated beyond reason as he has 20 doubles and 7 trips in 287 BA's. In the last 28 days, Morrison is a .289-.379-.356 hitter. He's has 3 XB's in 103 PA's. But this is an interesting Morrison to bat near the top of the lineup. His rookie year he bated 2nd almost exclusively. Vs. RHP he is OPS'ing .809....he was at .797 in '10.4 months 2 days ago
moethedogI always said I liked that Morrison better. I would still get him some vL help in the form of Guti or Romero. Guti isn't the runaway that you might imagine....if you're going to platoon him. He's OPS'ing .776 vL in Tacoma with 1 HR in 51 AB's. Romero is at .895 and 4 in 67. (Montero, now blocked it appears is at .980 and 4 in 73: O'Malley is at .865 with a .404 OBP...He's better than Bloomquist). Guti is hitting RHP very well, but the LF position may be a platoon only deal right now. vR, you go with Trumbo, LoMo, Cruz and Smith......4 months 2 days ago
DaddyOAha. Things begin to add up. Jack is determined to keep Ackley. Brings in Weeks so somebody understands what he's going through. McClendon know that. (jk)4 months 2 days ago
moethedogWeeks and Ackley were both #2 picks.4 months 2 days ago
rick82Weeks must be real good in the clubhouse. I didn't realize what a young phenom he was, although he was a super high pick I figured he had a typical minors experience. But he skipped high A, going from the Midwest League at age 20 (and a callup in September to the big club) to AA at age 21, then half a season in AAA before settling in as the Brewer second baseman. Only 937 PAs in the minors, a hundred or so fewer than Ackley.4 months 2 days ago
GrumpyAckley rather.4 months 2 days ago
GrumpyIf he gets hurt plug-in actually back in and call up Jones.4 months 2 days ago
GrumpyYes I can't imagine what the holdup is on Gutierrez.4 months 2 days ago
MtGrizzlyCrappy thing is, there's an extreme shortage of decent catchers in the game right now. Tough and expensive position to upgrade.4 months 2 days ago
rick82Over that last week, Zunino has an .000 BA with a .214 OBP. 3:4 BB/K ratio.4 months 2 days ago
SABR MattTerry...Rodney is demoted...Smith is the closer now. Only 3 blown saves before Rodney disappeared. That's pretty fast.4 months 2 days ago
phxterryPersonally, I think that GMZ had a very good off-season, plugging several major holes with Cruz, Smith, and Happ -- without significantly down-grading the talent pool. I would fault him for being slow to react to correct deficiencies as the season has developed; however, he did make a nice trade for a back-up catcher when Sucre flopped at the plate. For me, most of the fault is with the manager and players. The Pencil's inherent stubbornness for playing the wrong players (his man-crush on Almonte has been replaced with his love for the FRE) has not been offset this year with the magical touch he had in the bullpen last year. I reckon that the Pencil's use of Rodney and Farquar is, by itself, the difference between the current record and .500.4 months 2 days ago
Gordon GrossLOL or what Matt said. Carlos is OPSing a thousand in the minors this year. Montero: .830 (and blocked by Trumbo), Marte: .830 (and injured), Romero: .820 (and currently injured), Taylor: .800 and back in AAA for a reason, Kivlehan: .760 with no walks, Jones: .690, DJ .575 in AA (!!!) and then Dario Pizzano who probably needs to move up to AAA with his current .850, good eye and slight lack of power - which is another great reason to promote Guti.4 months 2 days ago
Gordon GrossCorrea is a future monster. The Mariners were hoping Buxton or Correa got to them in that draft, and Zunino was the consolation prize. When his offense comes around in 2018 he's gonna be a great future prize - for the Yankees. Last night was Kivlehan's first walk in 2 weeks. He's hitting for power now (.305 average with a .625 SLG over his last 3 weeks) but the 4:22 eye over that time frame isn't great. I still don't call up Kivlehan, and Marte is on the DL at the moment. Montero has had his spot taken by Trumbo. That leaves Guti, who is posting a .326 /.422 /.533 /.956 line this year in AAA with a .6 batting eye. He can come back up aaaannny day now and take Ackley's spot. DFA Weeks if that makes you feel better, since they're both righties. We need Guti's D out there and his offense CAN'T be as bad as everyday Dustin.4 months 2 days ago
SABR Mattmoe...we don't have anyone with Correa's pedigree knocking down the door. Our AAA hopefuls are MLB vet retreads, guys who are hitting .210, and guys with K/BBs larger than 5.4 months 2 days ago
DaddyOIt is a little known fact that The Beatles had mystic powers, and forseeing the dreadful lot of Mariners fans in 2015 composed this song to capture their mood: months 2 days ago
moethedogA day off and a plane trip east......The perfect time to make some roster moves. Man, Houston just called up their 20 year old SS, after a handful of AAA games.....because he's better than their other guys. Exactly what we should be doing.4 months 2 days ago
DaddyODay off. A vacation from Mariners Fan Misery.4 months 2 days ago
MtGrizzlyThey like Weeks for some reason.4 months 2 days ago