By The Numbers: Modified Slugging Percentage

Mathematicians love to tweak formulas, and baseball fans love to see sluggers. So for this episode of By The Numbers, we will look at the well known slugging formula of Slugging Percentage (SLG). As we know,

where TB stands for total bases and AB denotes at-bats. We see that walks (W) are not taken into consideration, though W do have a very definite positive value for the team which is batting.

Suppose we modify our SLG formula to incorporate W as follows:

where MSLG will stand for Modified Slugging Percentage. In effect, we are treating W as if they were Singles, although the possibility of moving runners more than the one "forced base" that follows from a W not apply. Nevertheless, let us see how some past and present sluggers "improve" with this new metric. We note that we have used statistics for active players, such as Albert Pujols, which have been recorded thru the end of August.

As we can see, Babe Ruth tops the list with .751, the only player in history to break the .750 barrier. The Thumper, Ted Williams, is the only other slugger to be a member of the ".700 Club", trailing the Bambino by fifty points. Lou Gehrig, at .691, ranks next, closely followed by Barry Bonds.

Among active players, St Louis Cardinal Albert Pujols, at .677, easily leads the pack. In fact, as Prince Albert approaches his prime, it not unreasonable to envision him surpassing even Ted Williams, winding up second only to the Bambino himself.

Regarding seasonal highs, Barry Bonds' MSLG of .900 obtained in 2001 tops the list with Babe Ruth's 1920 mark of .885 a shade behind.

We end this short blog with a question: Is there a way to modify the MSLG metric to incorporate other factors or terms such, for example, as Hit-by-Pitch (HP)?

Next Blog: What is the Power-Speed Number?