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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Bat571And, as I noted in another shout, a deal for Kemp will probably also cost at least 1 bullpen arm; which could mean another chunk off the final amount if it's Wilhelmsen, and a trim if it's Furbush. I'm making the assumption that Erasmo is gone, either to Atlanta in trade or, being out of options, is traded for a propect; that Ackley makes the most sense for the Braves in trade for Gattis; and that Taylor would be an MLB piece in a trade for Kemp. I assume any remaining pieces will be prospects (Guerrero, Morban, Choi), even if Terdoslavich would come with Gattis.4 hours 43 min ago
Bat571Just using the TNT tool -- http://www.thenewstribune.com/2014/11/04/3467689/seattle-mariners-2015-free-agent.html -- and adding Gattis ($0.5M - using another FA as proxy), Kemp ($16M - using another FA as proxy), Young ($7M), and HanRam ($22M), and then manually subtracting Ackley, Taylor, and Erasmo ($3.8M total) gives ~$137M. Take HanRam's $22M out and that gives ~$115M, which is $8M more than the $107M. The TNT tool uses the $5M figure for Seager and the $7M figure for Iwakuma. Given the offers for Martin and VMart, I think there's more than $8M in headroom, in any case.4 hours 56 min ago
SABR Mattnot sure where you get 8 mil, Bat...Gattis is cheap but Kemp at 16 mil, Young at 5-6 mil, Iwakuma at 7 mil, Seager at 5 mil...did you factor those in? I get roughly 14 mil up from 107 if we add just Kemp/Gattis.5 hours 20 min ago
Bat571And after Mather promised substantial budget increases, $8M wouldn't be substantial in my mind.6 hours 3 min ago
Bat571Well, If The Ms got Kemp and Gattis and re-signed Young, it'd be a dandy off-season, for sure. But it's Christmastime and I've always got to hope Santa's bringing me that new Volvo XC-90 with the 450HP hybrid drive train that gets 34mpg, even while I'm still driving my 2003 Honda Pilot!6 hours 13 min ago
moethedogToo many moving parts, Bat. Hope for one big guy....or Gattis plus6 hours 26 min ago
Bat571If Wilhelmsen went in trade for Kemp, that takes another $2.1M off, Furbush $1.0M, Medina $0.5M. In any case, I really believe it's doable. And if Chris Young would sign to smooth innings, I continue to think rotating Elias, Walker, and Paxton to Tacoma for 10+ day stints of 4-5 inning starts to keep their totals down would be workable. Then Young could skip starts in places like Texas as well. BOAPW! (apologies to Prof. Pangloss and Voltaire).6 hours 45 min ago
Bat571$30M increase, not $20M - typo.6 hours 54 min ago
Bat571I put the numbers in the TNT payroll tool (since it doesn't do trades, I used a Chone Figgins FA signing @ $16M as a proxy for Kemp - I know, SICK!). With HanRam @ $22M, Kemp @ $16M, and Chris Young @ $7M, it totals to $141.1M. Subtract Ackley, Taylor, and Erasmo, and it looks like ~$137M - a $20M increase over the $107M end number last year that Mather implied was the starting point for increases.6 hours 56 min ago
SABR Mattif we could get the Dodgers to front-load their subsidy...pay us like 15 mil in 2015, 12 mil in 2016 and 8 mil in 2017 and then off the hook thereafter...we could ease the transition, from a payroll perspective...soften the blow to the finances on the front side.7 hours 14 min ago
moethedogLA will have a RH bat in the pipeline, perhaps Hanley, if they are really trading Kemp. Matt is right. We get only one big ticket guy. That's it.7 hours 15 min ago
SABR MattI hope you're right Bat...because a rational analysis of the team at this point says it's stupid not to spend big and win now...Cano and Felix in their primes for only so long...kids maturing and just got valuable play-off race experience, attendance tentatively rising...if you were ever going to fight hard...this would be the time.7 hours 17 min ago
Bat571Gattis is still pre-arb, so his price is the trade cost (Ackley?), but little initially to the payroll. If Kemp came at a payroll cost of $16M (~2/3-1/3 split), and HanRam comes in at the MLBTR prediction of $22M (AAV), that's a $38M add. From where they're at now, that looks like <$140M - but they would still have another signing (Chris Young) and extensions to Seager and Iwakuma to add to that, if it worked out like I'd like.7 hours 17 min ago
Bat571It would depend on how much subsidy the Ms could get with Kemp, but the amount they bid on VMart and Martin makes me believe they may be willing to go near $140M at least -- they seem to understand the amount spent on Cano and Felix will be wasted unless they go for it starting now. And that would be enough.7 hours 29 min ago
Bat571And a bench of Saunders (OF); Terdoslavich (1B/3B/COF); Bloomquist (IF/OF); and Sucre (C) - with Bloomquist and Sucre ceding to Kivlehan and Hicks by the AS Break.7 hours 34 min ago
SABR MattGetting both Ramirez and Kemp is not possible...unless the Mariners suddenly decide they want to spend 150 million on payroll.7 hours 38 min ago
Bat571Meanwhile, we can dream of a Jackson-HanRam-Cano-Kemp-Seager-Gattis-Morrison-Zunino-Miller lineup laying waste to the AL.7 hours 46 min ago
Bat571Yes, Moe - like they've realized they will have problems if they move Kemp from RF that might outweigh the loss of the RH bat. Would they turn around and trade for a cheaper, younger guy? Sign Rios? Dunno - but somebody ought to keep whispering "2016 - Guerrero-Pederson-Puig" in the ears down there! And "Taylor and Gordon stealing 40 bases apiece and turning DPs nightly" as well!7 hours 49 min ago
Bat571And I still think Terdoslavich is just where Scott Van Slyke was a year or so ago - getting old for a prospect, blocked at his best position, able to play other positions adequately, good MiLB numbers that translate to MLB effectiveness, and ready to put the hurt on pitchers if he can get a chance. The injuries to Kemp, Ethier, and Crawford gave SVS his chance. I'd really like to see Terdoslavich get a chance in Seattle while Kivlehan and DJ get their ABs in Tacoma. And Morrison has not been durable - do we really want to try Montero there as a starter if Morrison goes down?7 hours 58 min ago
moethedogInteresting report on Kemp. Almost like something is in the works.8 hours 4 min ago