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Velocity loss of a pitched baseball (June 10, 2003)
Discussion ThreadPosted 12:05 p.m.,
June 12, 2003
(#2) -
JohnW
Robert Adair in The Physics of Baseball addresses this very question. I don't have the book in front of me, but his calculation (I believe) is more precise than the one above.
One problem I noticed (there may be others) with the calculation is that the time of flight of the ball on its way to the plate assumes a constant velocity, i.e. time = distance/velocity. But the velocity is not constant, indeed it's the change in velocity that is being calculated! Also, the drag on the ball is proportional to velocity squared, so as the ball slows down the drag is reduced and the deceleration is also reduced.
Velocity loss of a pitched baseball (June 10, 2003)
Posted 3:55 a.m.,
June 13, 2003
(#3) -
JohnW
Just a follow-up to my previous post. I checked Adair's book and he says that a pitched fastball loses about 7 mph per foot of distance traveled. The effective distance to home plate is somewhat less than 60'6", so the average velocity loss is about 8 mph for a mid-90's fastball. That's actually pretty close to what Carmichael found above, although I think the agreement is somewhat fortuitous.
SABR 201: Linear Weights by the 24 base/out states, 1999-2002 (June 10, 2003)
Posted 12:13 p.m.,
June 12, 2003
(#10) -
JohnW
Very interesting stuff. Am I reading the table correctly? I notice that with a runner on 2nd and nobody out, an IBB has a negative value. Does this mean "the old school" is correct and managers should be calling for 4 straight after a leadoff double?
That seems to fly in the face of conventional sabermetric wisdom.
SABR 201: Linear Weights by the 24 base/out states, 1999-2002 (June 10, 2003)
Posted 3:52 a.m.,
June 13, 2003
(#12) -
JohnW
The chain of batters are not necessarily random (well, they probably are in the first case), and certainly not random in the second set.
Hmmm, does this mean that in the particular cases where the IBB was issued we don't know what the run expectancy would have been had not the IBB been called for? And therefore we cannot judge if the IBB was a valid strategy or not?
Let me ask a direct question: can one tell from the results in your table if the IBB strategy with 0 outs, runner on 2nd, is a good one?
thanks.