By Roger Weber

 

Die hard fans often believe that baseball needs a 162-game season because that is the only way the best competition can separate itself from the worst. It is true the difference between the best and worst teams in baseball is less than it is in any other major professional sport. In football some teams finish 3-13, some 13-3. The best team can play the worst team ten times and the best team will likely win 8 or 9 of those times. In baseball, though, over those ten games the best team might win as many as 8 or 9 or as few as 3 or 4. Most likely, though, they will win about six.

 

The best teams in baseball win about 60% of the time and the worst teams 40%. On any given day any team can win against any other team. A team can win 11-0 one day and lose 12-2 the next. So if the best team is only 20 winning percentage points better than the worst, does a bad team have a chance if it gets lucky to make the playoffs? It doesn't seem likely but it is certainly possible and happens more than you might think.

 

In 2005 only two teams had lower total batting averages than the Chicago White Sox. And two had better team earned run averages. But the White Sox had by far the best record in the league? They only lost one game in the playoffs. They may have been the best team, but they may not have been. Even if they were only a slightly better than average team, a 99-63 record wasn't beyond the realm of reasonable probability.

 

There is a way of finding statistically how far above or below average a statistic can be before it can be said that it isn't due to chance, that there is something causing it to be higher lower than average other than a sample size that is just too small to give an accurate result. This is called a confidence interval. It measures the number of standard deviations away from average that a statistic is and defines whether that statistic falls within a certain interval that includes possible numbers caused by nothing but chance.

 

If you flip a coin five times and get four heads, that doesn't seem out of the question, but if you flip in 1,000 times and get 800 heads, then you may want to see if the coin is weighted evenly. The same type of analogy is true in baseball. Over ten games any team can finish with any record. If the worst team goes 8-2 over a ten game stretch we might say they are "hot" but this surge of winning is likely due to just chance. If they were to play 1,000 games and finish 800-200, though, we could probably say that something is causing them to finish with that strong a record.

 

So over different numbers of games, teams can win different numbers of games. Usually the winning percentage gets closer to a team's actual talent level with more games played. But a 162-game season isn't so long that an average team can't finish with a playoff worthy record.

 

Here's a chart of maximum numbers of games an average team might win or lose facing average competition due to chance. This uses a 95% confidence interval, a commonly used interval that means that the interval we choose has a .95 probability of containing the actual result.

 

	Avg. wins	Min. wins	Max. wins
30 games into season	15	9	21
60 games into season	30	22	38
100 games into season	50	40	60
Full season	81	68	94

    

An average team can win as few as 68 games or as many as 94 and still be called average, with a record that good or bad due to just chance. Of course they're most likely to have a record somewhere around 81-81 but these are limit figures to tell us just how much chance affects baseball. So what about those White Sox?

 

They were better than average. We know that from our confidence interval. But according to this interval, they could have been a team whose true talent over an infinite number of games would have merited them 53% wins, 47% losses on the low end, or 69% wins, 31% losses at the high end. Now their impressive start in 2006 gives us more data and more evidence to support the claim that they were a very good team worthy of winning nearly 100 games, but just because a team wins 100 games doesn't mean its talent equaled that total.

 

Something worth noting is that the overall field of competition is even closer than the records suggest. The best teams benefit in their records by not having to play themselves 19 times and poor teams suffer in the standings often because they do not get to play themselves, an opponent that might make an easy win or at least a good game.

 

The worst record of a team to win the World Series was 85-77. If a team can get into the playoffs with a record like that, then statistics tell us that a team with talent equal to a 44% winning percentage can make the playoffs. And if 85 is the cutoff line, a team with the talent worthy of 60% wins can miss the playoffs.

 

But this isn't to say that the good teams don't usually make the playoffs. Usually the best teams are in the playoffs. In 2005 the Padres got in with an 82-80 record. But that's a rare case. The chance of a bad team making the playoffs is far slimmer than the chance of an average or good team playing in October, but it isn't out of the question.