Before we think in terms of a measure for offensive ability, we have to understand what offence consists of. The goal of a baseball game is for your team to score more runs than the opposing team. Runs are scored when a player advances through all the bases and reaches home plate. So, moving up through the base pads is the primary focus of each batter. Hitting, walking and stealing all move the player up the bases. Thus, it can be argued that offensive ability is hitting ability plus ability to steal bags plus ability to reach base on balls.

None of the current measures do justice to all aspects of offence. Let us look at the current measures commonly used:

1. Batting average (BA): This is a great indicator of a players hitting ability. But, offense consists of not just hitting ability, but also speed on the bases. Besides, BA completely ignores a disciplined hitters ability to reach base on balls (BB).
2. Total Bases: Again, total bases measure (TB) indicates a player’s hitting success – but, it ignores stolen bases and bases on balls completely.
3. Runs Scored: Some may argue that a player’s run count is a good measure of offence. But, outside of home runs, a player owes runs to his teammates’ performance at the plate.
4. Runs batted in (RBI): Probably a better measure than runs scored, it indicates a player’s ability to hit with players on base, i.e., in the clutch. Obviously, players who hit homers score themselves in. But, a player’s RBI count is dependent on other player’s presence on bases, not to mention the opposing team’s decision of whether to pitch to him or not when players’ are on base.
5. On base percentage (OBP): A better measure of offence, OBP neglects the key element of stolen bases.
6. Slugging percentage (SLG): This is an excellent measure of power. However, it fails to account for the base on balls and steals in its measure.
7. On-base plus slugging (OPS): This is just the sum of OBP and SLG.

As can be seen, all existing measures of offence have limitations. So, here is a measure that eliminates all shortcomings with existing measures:

Total Offence (TO) = (Total Bases + Bases on Balls + Stolen Bases)

And, then the player’s offence effectiveness is defined as:

Offensive effectiveness (OE) = Total Offence (TO) / Total Plate Appearances (TPA)

In effect, offensive effectiveness (OE) is an indication of how many "bases" the player took per plate appearance. OE is the best measure of offensive ability that takes into account all elements of offence, i.e., hits, walks and steals.

So, I checked the offensive percent of the top 100 MLB players with the most at bats. Only 2 players had OE of higher than 0.70. And, not surprisingly Babe Ruth was the numero uno player with an OE of 0.763. Right behind him is Barry Bonds with an OE of 0.731 (includes his stats till Aug. 25, 07).

Interestingly, Alex Rodriguez has an OE of 0.655 and Albert Pujols 0.678. The OE scores of other players (as of Aug. 25, 2007) is at this link; http://www.cylive.com/viewContent.do?id=1613.