The essence of winning baseball games is runs — scoring them and preventing opponents from doing the same. For many, the Ferrari Testarossa of scoring side stats is batting average. Sadly, that particular stat is more like a 2000 Lincoln Navigator; it looks impressive, but it's a costly disaster just waiting to happen.

If batting average were useful, it would correlate with runs scored; when a team's batting average went up, the team's runs would, too.

Frequently it doesn't.

Batting average doesn't properly differentiate between a Richie Sexson .270 BA that features healthy doubles and walks and a potlatch of homers, and an Alex Sanchez .290 BA thin on doubles and homers, with walks appearing about as frequently as Kenny G records a Pearl Jam cover.

You can see how different the two batters' contributions are when you look at their careers in "seasonal notation" (the average 162-game portion of their whole career).

You have one monster and one munchkin.

Batting average was popularized in the 19th century by Henry "The Exeter Executioner" Chadwick, the forefather of the first rule book. According to research by Mike Carminati of Mike's Baseball Rants Web log, in the play of that era, BA correlated very well to run-scoring. In the ensuing 125 years, every facet of the game has changed, but batting average has stayed right where it was, a festering artifact of the Rutherford B. Hayes era.

Closer to truth

Sabermetricians know that, to produce offense, a team needs batters who get on base, best reflected by on-base percentage. You also need batters who can knock runners in from as far as first base, best reflected by slugging percentage. Blend the two together and you get OPS (on-base plus slugging), a single number that accounts for both.

Definitions:

On-base percentage: (Hits+walks+hit-by-pitch) divided by (at-bats+walks+hit-by-pitch).

Total bases: Singles equal 1 base, doubles 2, triples 3, home runs 4.

Slugging percentage: Total bases divided by at-bats.

OPS: On-base percentage plus slugging percentage.

OPS+: OPS, adjusted for a batter's home park, then normalized so 100 equals the league average for that season.

HR%: The frequency of home runs.

So a team's OPS is a better indicator of the ability to score runs than any of those simpler measures. Teams with a higher OPS are very likely to score more runs than those with lower OPS. As you can see from Carminati's table accounting for 15 seasons' data, OPS correlates more closely with run-scoring over the season. Higher correlation indicates a stat has more to do with scoring runs than a stat with a lower correlation does. The stat in bold is the one that correlates most closely with run-scoring for that season.

In eight of the past 10 seasons Carminati examined, OPS is the stat that most embodies run-scoring ability.

Extend the logic from teams to players. If OPS is what makes a team successful at offense, then that's what makes the individual components of a team (its players) successful at offense.

Clearly, offense is more complex than any single stat can describe. Balance in the recipe is vital, too. True, Sabermetrics tells us a team of made up of hitters who were all Richie Sexson clones (.877 lifetime OPS) playing a full season against a team made up solely of Alex Sanchez clones (.691 lifetime OPS) would win 131 of 162 games. But those Sexsons would have problems against a more normal team that had a healthy blend of hitters expert at getting on base to complement their sluggers.

Still, if you're looking for a single offensive value that's not a nightmare to compute, OPS is a valid indicator.

More complicated than you'll want to do at home, but providing greater insight is OPS+. It indicates Mariners hitters are better than the raw OPS numbers show, because the number accounts for where you play your games.

The Mariners play half their games at Safeco Field, a park that significantly depresses hitting. That means their OPS is worth more than the number delivered by, for example, a Texas Ranger, who plays home games in a slugtastic park. The other tweak in OPS+ is that the stat is "normalized" to 100 — a score of 100 indicates the league average; e.g., a 116 is 16 percent better than average, and a 91 is 9 percent below average.

Every year there are some batters who hit .300 or better who don't walk much and don't hit for power often. Don't be fooled. They may complement their team's offense. They may be useful in the field or on the basepaths. They may be great human beings.

But they aren't very good major-league hitters when their OPS is below the league average.

Jeff Angus is a management consultant and author of the Management by Baseball Web log at cmdr-scott.blogspot.com and the book of the same name. He can be reached at jangus@seattletimes.com.