When Spring Training Stats Matter Part 2

I've been obsessed lately with this John Dewan nugget:

A hitter with a positive difference between his spring training slugging percentage and his lifetime slugging percentage of .200 or more correlates to a better than normal season.

To properly study this in regards to last year's Spring Training stats, I need some more info.  Specifically, what does "better than normal" mean?  Better SLG in the season compared to the guy's career SLG?  Better SLG this season than last?  Something else?  I shot Mr. Dewan an email in hopes of getting clarification.  I'd also like to know what sample size he considers appropriate.

That said, I still ate up a bunch of time running numbers with '07 Spring Training stats.  I found 34 non-rookies whose '07 spring SLG topped their career mark through '06 by .200 or more.  I defined an improvement as an '07 SLG better than the player's '06 SLG.  I used '07 vs. career if the player didn't play in the bigs or had a tiny sample for '06.  In red, I highlighted the 11 whose regular season improvement I truly feel may be linked to their Spring Training performance.  I used a 20+ AB spring sample.

NAME	ST SLG	Career	Diff	06 SLG	07 SLG	Improve?
Eduardo Perez	0.955	0.431	0.524	0.452	DNP	No
Scott Hairston	0.935	0.430	0.505	0.533	0.452	Yes
Pete Laforest	0.730	0.241	0.489	DNP	0.389	Yes
Ronny Paulino	0.833	0.395	0.438	0.394	0.389	No
Aramis Ramirez	0.851	0.493	0.358	0.561	0.549	No
Jeff Salazar	0.750	0.415	0.335	0.415	0.394	No
Khalil Greene	0.763	0.434	0.329	0.427	0.468	Yes
Reed Johnson	0.750	0.423	0.327	0.477	0.320	No
Greg Dobbs	0.672	0.351	0.321	0.556	0.451	Yes
Derrek Lee	0.809	0.500	0.309	0.474	0.513	Yes
Chone Figgins	0.697	0.393	0.304	0.376	0.432	Yes
Ryan Spilborghs	0.735	0.433	0.302	0.431	0.485	Yes
Gerald Laird	0.703	0.401	0.302	0.473	0.349	No
Brandon Phillips	0.676	0.375	0.301	0.427	0.485	Yes
Ramon Castro	0.686	0.387	0.299	0.389	0.556	Yes
John Mabry	0.706	0.407	0.299	0.324	0.235	No
Carlos Quentin	0.821	0.530	0.291	0.530	0.349	No
Raul Ibanez	0.750	0.469	0.281	0.516	0.480	No
Sammy Sosa	0.816	0.537	0.279	0.376	0.468	Yes
Josh Phelps	0.737	0.473	0.264	DNP	0.503	Yes
Barry Bonds	0.867	0.608	0.259	0.545	0.565	Yes
Brad Hawpe	0.722	0.464	0.258	0.515	0.539	Yes
Johnny Estrada	0.661	0.407	0.254	0.444	0.403	No
Jose Guillen	0.691	0.445	0.246	0.398	0.460	Yes
Bobby Abreu	0.750	0.507	0.243	0.462	0.445	No
Brian Schneider	0.629	0.386	0.243	0.329	0.336	Yes
Adrian Beltre	0.683	0.457	0.226	0.465	0.482	Yes
Adrian Gonzalez	0.700	0.475	0.225	0.500	0.502	Yes
Brad Eldred	0.682	0.458	0.224	DNP	0.261	No
Jose Cruz	0.653	0.431	0.222	0.381	0.375	No
Chase Utley	0.727	0.509	0.218	0.527	0.566	Yes
Milton Bradley	0.643	0.429	0.214	0.447	0.545	Yes
Ian Kinsler	0.667	0.454	0.213	0.454	0.441	No
Ross Gload	0.643	0.437	0.206	0.462	0.441	No

• 11 semi-breakouts among 34 - is that helpful?  Tough to say, but if you're on the fence on a guy and he tops his ST SLG by .200 then maybe you should give him the benefit of the doubt.
• Plenty of the "no improvement" guys had extenuating circumstances - Reed Johnson had back surgery, Laird was catching full-time for the first time, Quentin was hurting.
• Seems like this stuff matters less for veterans (Abreu, Ramirez, Ibanez), but then again young guys naturally improve regardless of spring training.  Hard to sort it out.
• Several rookies had big springs.  Hunter Pence, Ryan Braun, Billy Butler, and Mark Reynolds were among last year's ST SLG leaders.  They all went on to have solid rookie campaigns.  There may be something to that (though Cameron Maybin slugged .905 in spring and nothing came of it).

Comments

[IowaCubs]

Tim, are there any rookies out there having strong springs?

Looking at stats thus far, I see strong starts for Lastings Milledge, Steve Pearce, Chase Headley and Maybin.

[finite24]

IowaCubs: Butler, Milledge, and Chris Snyder will be three guys with a yes next to their name when we look back on the 2008 ST list next year.

[finite24]

Tim,

Gotta start trusting me on including Chris Snyder in with Ruiz and others as a great late round 2nd catcher. I saw that you didn't mention him in your THT mailbag.

[Tim Dierkes]

I didn't, but I agree with you. That is another good one, especially with Montero out.