THE BOOK--Playing The Percentages In Baseball

Note that all of his graphics refer to the spin-induced movements of the pitch (i.e., gravity and time are not part of the equation).  What is interesting about the knuckleball is that it actually changes its spin rotation or axis on its flight toward the batter.

I what makes the knuckleball interesting is that it is completely different than every other pitch.  Magnus force (the force caused by spin and resistance) is not the cause of the ball breaking as with a normal pitch.  The near lack of spin causes more drag on one side of the ball, resulting in the ball moving in that direction.  The knuckleball that moves more than once is more a fact of the ball experiencing drag on different parts of the ball during a pitch, rather than the spin axis changing.

Regardless, the knuckleball might be the single most interesting and unique aspect of baseball.

ElBonte, let’s assume a knuckleball has no spin whatsoever when it leaves the hand.  Are you saying that the orientation of the ball (and thus, seams) actually impacts it’s trajectory?

I was under the impression that a knuckleball moves almost exclusively as a function of the wind currents.  Or are you saying these wind currents are what create the drag?

Awesome, awesome article at Hardball Times.  I really enjoyed it.

Are you saying that the orientation of the ball (and thus, seams) actually impacts it’s trajectory?

Exactly.  The wind also plays a part in moving the ball, but the “dancing” movement of the knuckleball is produced by the orientation of the seams on the ball as it slowly rotates on its way to the plate and not by the forces produced by the spin.

Check this site out on the physics of a knucklebal’s flight. It has some nice wind tunnel photos that illustrate the physics.

http://www.oddball-mall.com/knuckleball/mego.htm

So if we’re looking at the variability in movement of the knuckleball… again assuming 0 spin… part of it is random (wind) and part of it is predictable (orientation of ball).  Do you think Wakefield alters the orientation of the ball to impact what it does?  It seems like you’re saying the impact of orientation, which is predictable, outweighs the impact of wind, by quite a bit.  If so, the knuckleball should be a lot more predictable for the pitcher than we think (and for the batter as well, if he could pick up the orientation of the ball as it leaves the hand).

I have not RTFA yet, but I have always wondered whether a knuckler like Wake has the abiity to throw to different locations in and around the zone.  If not, he gives up the opporunity to pitch differently depending on the count, hitters, runners on base, etc. and consequently his ERA will exceed his ERC, as compared to other pitchers. Any thoughts?

For example (of many) with a runner on 3rd and less than 2 outs or when needing a GDP, a pitcher will try and throw pitches lower in the zone, with a runner on second and 0 outs, he’ll try and keep the batter from hitting the ball to the second base side, with a big lead or with a non-power hitter at the plate, or to a leadoff batter in each inning, he’ll throw more strikes.  Etc., etc. 

Can Wake do this with the knuckle ball or does he pretty much try and throw every ball to the same location in all situations?  If yes, that is a severe disadvantage to have to overcome.

OK, I just RTFA.  Great one, BTW.  John’s analysis is once again spot on, including when he doesn’t have enough data, isn’t sure about something, etc.

I have a couple of comments/questions.

John says that Wake just “aims for the catcher’s mitt” and hopes for the best.  We have all heard that before I think.  John doesn’t know that that is true.  If he only throws a few more balls on the KB than the MLB average, why can’t he aim for different spots depending on the count and game situation?  As I said in my previous post, if he can’t adjust location to the count and game situation (other than throwing more or fewer fastballs), he is “starting out” with a large disadvantage AND you cannot use context-neutral stats to predict ERA for him as you can do with most other pitchers.

If he has success with his fastball when he throw it, which he seems to do, mainly from the surprise element, it appears as if he throws it WAY too infrequently (almost not at all - .02 or so) when ahead in the count.  The numbers from John actually seem to suggest that KB is about as good as the average MLB pitch and that Wake’s advantage comes from the occasional non-KB.  Again, if that is the case (it might not be, given the sample sizes of the data), then he definitely should be throwing the non-KB more when ahead in the count.

What is an OPS on a pitch?  How is that calculated?

I would love to see his pitches cross-referenced with weather (wind location and direction) or just outdoors versus indoors.  It is believed by some that the weather plays a role in how effective a KB pitcher is.

I would like to see location of the KB plotted against the count (and/or score, outs, baserunners, type of batter, etc., as compared to the average MLB pitcher) to help answer our question of whether he changes his location with the game situation.  Again, for example, one reason why power (and good ones in general) hitters generally get more walks than non-power (and poor ones) hitters is that pitchers throw more pitches out of the zone.  I would like to know if Wake can do that.  One way would be to look at his walk rates versus high SLG batters and low SLG batters and see if the differential is the same as with the average MLB pitcher.

Mike/#5:
I think there’s a problem with saying that part of it is “predictable”.  We’re talking about very small differences in the orientation and spin (both the rotational speed and direction) of the ball resulting in huge differences in the movement. 

There is also the so-called “ferris wheel effect” described in the link in #4.  This means that, effectively, the orientation of the ball changes even with no spin.  To say that any part of the movement is predictable is an extreme over-simplification of a very complex system.

I can’t claim to know, for certain, what role wind plays in the pitch.  That factor is rarely mentioned when seeing a physics-based analysis of the knuckleball.

Let’s all hope for a few more years from Wake’ so we can get a good set of Pitch F/X data for analysis.