mushbone wrote:

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Nexus wrote:

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Pay attention to K and ISO rates when comparing BABIP. Using an extreme as an example, Ryan Howard's career BABIP is .332, which makes sense considering his lifetime .277 average is coupled with a .305 ISO, but a 33.1% K rate. On the flipside, Pedroia's career .308 average is very close to his .319 BABIP, thanks to a smaller K and ISO rate. There are obviously other variables that come into play (speed) but I always immediately look at a players K/ISO rates next to their BABIP and compare it to their career averages to see if they are getting "lucky" or not.

Kalish 18.8% K rate (around career norm) coupled with his .157 ISO (below career norm) in AA proves Cem is right. Kalish's current .309 BABIP (below career norm) is probably attributed to defensive swings that produced a lot of choppers early on.

Using Austin Jackson as an example of someone who I think is lucky this year, his .300 average doesn't look as good when factoring in his 25.6% K rate, a .115 ISO - with a BABIP of .394... and the correction is starting to take place as his numbers are falling back down to earth.

Jesus Montero on the other hand, is a really good baseball player (with the bat, at least).

I certainly understand why it's important to look at K rate in conjunction with BABIP, but why look at IsoP? Other than the indirect connection to home run rate, what difference does this make? Why not just use the direct rate of home runs per AB instead? And isn't LD% more important than either of these two factors in explaining a higher-than-average BABIP?

Check it out for yourself. Compare past BA to BABIP, then look at the K% and ISO numbers. His LD% is down from earlier in his career, yet his BABIP stays consistent. I think you can contribute this to a higher ISO the last two years (and not just HRs).

This "formula" will not apply for every player, but it certainly does for Youkilis... and we can conclude he's having a "luckier" year this year v. '08 based on higher K%, higher BABIP, but similar ISO from the previous year.

mushbone wrote:

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Nexus wrote:

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Check it out for yourself. Compare past BA to BABIP, then look at the K% and ISO numbers. His LD% is down from earlier in his career, yet his BABIP stays consistent. I think you can contribute this to a higher ISO the last two years (and not just HRs).

This "formula" will not apply for every player, but it certainly does for Youkilis... and we can conclude he's having a "luckier" year this year v. '08 based on higher K%, higher BABIP, but similar ISO from the previous year.

You still haven't shown any relationship, much less explained one. If you want to claim that a high IsoP is key to having a high BABIP, you've got to say why, not just show one isolated example, especially when a counterexample is easy enough to find.

IsoP is just another way of expressing total bases per hit, and BABIP is calculated from hits, not total bases. A high IsoP is usually going to have a depressive effect on BABIP because home runs are removed from consideration and reduce both the numerator and the denominator of the fraction by the same amount (K's have the opposite effect - they reduce the denominator only and always boost BABIP). Extra base hits other than home runs, although they increase IsoP, have zero effect on BABIP.

Since home runs and Ks have opposite effects on BABIP, it's hard to see how those two factors are both highly correlated with high BABIP. If you're postulating that some unnamed factor is responsible for or related to all of them (high K rate, high IsoP and high BABIP), I'd be interested in hearing what it is.

I never said higher IsoP equals higher BABIP. I look at the relationship between BA, BABIP, K%, and IsoP to determine if a player is lucky. In the case of Youkilis, he was a consistent .275-.280 hitter, with the same K% and LD%, and a .335+ BABIP through the first few years in the league. It wasn't until last year's boost in IsoP did we see his BA (not BABIP) go up. His BABIP remained constant from his career norms. Last year, I think his higher IsoP boosted his BA closer to his BABIP. This year, I think his high BABIP has made him lucky because his K rates are at career highs, but he's maintained the same IsoP from the previous year... therefore his BA is right in line with last years average.

As for Dunn, I can't really explain how his .349 BABIP is 66 points higher than his current BA, especially when his K rates are the same and his IsoP is above career norms. Like I said, it won't apply for everyone.

But Pujols is another example. Again, look at the relationship between all 4 categories above. K rates are constant, but in the years where his IsoP numbers are off the charts, look at his BA compared to his BABIP. And look at them when his IsoP numbers are lower. I don't think it's coincidence.

mushbone wrote:

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Nexus wrote:

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I don't think it's coincidence.

I do. There is no reason to believe it's significant.

If K% remains constant, then higher IsoP means less discrepancy between BA and BABIP. Look at just about any player and this relationship applies, with speed guys being the exception.