Evaluating Baseball Offense

Today, we at MLB Daily Picks, are writing about baseball offensive evaluation. Most commonly used offensive baseball stat is batting average. Batting average is calculated by dividing number of hits with number of at bats:

AVG = H / AB

Season batting average higher then .300 is considered to be great, season average between .230 and .300 is average and anything bellow .230 is considered poor.

Although most used, this stat in my opinion and in my experience is not as relevant as some other offensive stats. Let me explain why. First of all there is no direct correlation between batting average and runs scored, and when talking about baseball offense, run scored is an ultimate goal.

Batting average is supposed to be a measure of how often a batter gets on base, but this is not completely true because batting average is not taking into account all the situations when hitter can reach first base. This is because batting average is calculated using at bat. Every time hitter comes to plate he starts with at bat, but he can get „no time at bat“ in following circumstances:

• when he is hit by the pitch
• when he hits a sacrifice fly or a sacrifice  bunt
• when he is walked
• when he is awarded first base due to interference or obstruction
• when the inning ends while he is still at bat (if for example third out is reached by a runner caught stealing)
• when he is replaced by another hitter before his at bat is completed

So, we can see that there are number of ways a hitter can reach first base that are not included in batting average.

A stat that includes those situations is On-base Percentage (OBP). OBP is a measure of how often a batter reaches base for any reason other than a fielding error, fielder’s choice, dropped/uncaught third strike, fielder’s obstruction, or catcher’s interference. OBP is calculated by dividing the sum of hits, walks and hit by pitch situations with sum of at bats, walks, hit by pitch situations and sacrifice flies:

OBP = ( H + BB + HPB) / ( AB + BB + HBP + SF)

For me, one of the most important factors when evaluating teams offensive abilities is their OBP. OBP shows us how often runners get on base. More runners team has on base, more runs they will score, less runners on base less runs, as simple as that.

Teams with higher OBP are making opposing starting pitcher work harder, throwing more pitches. When starting pitcher reaches certain pitch count he is taken out of the game. If this happens early in the game (earlier then 6th or 7th inning) he will get replaced by a long reliever, a pitcher that is not so good. Best offensive teams are not just scoring more runs, they are making it easier to score more runs by taking starting pitcher out of the game earlier.

Let’s imagine a situation when we have a game with two equal starting pitchers and one team has  .350 OBP and the other team has .325 OBP. Chances are that team with a higher OBP will „take out“ opposing starting pitcher an inning earlier (at least) and that will give them more at bats against not so good reliever, which can result in more runs scored. Team with lower OBP will allow more innings to opposing starting pitcher, and when he finally leaves late in the game he can be replaced by good set up man and finally with a closer. In turn, this results with less runs scored for team with lower OBP.

So, the handicapper who only considered starting pitchers saw this game as equal, but the one that considered OBP saw the edge and took the team with higher OBP.

There is another significant offensive stat and that is Slugging Percentage (SLG). SLG is a measure of the power of the hitter. It’s calculated by dividing total bases with at bats, where total bases is a sum of singles, doubles, triples and home runs:

SLG = ( 1B + 2*2B + 3*3B + 4*HR) / AB

Importance of Slugging Percentage is in that when it’s combined with On-base Percentage it gives a new stat called OPS (On-base Plus Slugging). OPS is a measure of a player’s overall offensive production.

SLG and OPS are more important on a player level, to determine how good hitter player really is and they are maybe as not as important on team level.

When I’m evaluating teams offense most important factors for me are OBP and number of runs scored. Team that scores more runs on average will win more games and that is only important when handicapping baseball games.

If we take a look at current OBP stats (this was written on May 13th), we can see that top 2 teams in OBP are NY Yankees and Minnesota, two teams that are tied for second in wins in entire MLB. Last 3 teams in OBP are Baltimore, Pittsburgh and Houston and they are ranked between 25th and 30th (last) in MLB in wins.

Two top teams in runs scored are again NY Yankees and Minnesota and 4 bottom teams in runs scored are Baltimore, Seattle, Pittsburgh and Houston and they are all ranked in 5 worse teams in wins in MLB.

All the best

Mr. Stretch