1897 to 2011 : Winners v Losers - Leads, Scoring Shots and Conversion

In the previous blog, among other things we analysed which quarter winning teams win.

We might also ask of winnng teams, in what proportion of games do they trail at the end of a particular quarter, and how has this proportion tracked over the seasons.

The top line of the chart above tracks the proportion of games in a season in which the eventual winner trailed at the end of the 1st quarter (drawn games have been ignored here and throughout the analyses performed for this blog). Across history, this proportion has varied between about 20% and 50%, and has averaged around 32%. It's also been fairly stable for about the last 20 years.

Next, the middle line tracks the same proportion but for the winner's situation at half-time. This proportion has tracked in the 4% to 40% range, averaging about 21% and exhibiting relative stability for an even longer period - about the last 50 years.

Finally, the bottom line provides the information for the situation at the final change. This proportion has moved within a much narrower range, just 4% to 25%, averaging about 14%. It's also been stable for about the past 20 seasons.

Here's the same data summarised by era:

In summary then, in modern times, winning teams lead or are at least tied: 

• About 70% of the time at the end of the 1st quarter
• About 80% of the time at half-time
• About 90% of the time at three-quarter time

This season, so far, these percentages have all been a little higher as, for the most part, favourites have led and won most games.

One other aspect of winning teams' performance that I want to review in this blog is the proportion of games in which the winning team produces more scoring shots than its opponent or converts those scoring shots at a higher rate, and the proportion of games in which it does both.

Winning teams, it turns out, produce more scoring shots than their opponents far more often than they convert these opportunities at a higher rate.

In a typical season, winning teams will produce more scoring shots than the losing team in about 80-90% of games, but they'll have a higher conversion rate in only about 60-70% of games. In only a little under 50% of games will they both outscore and outconvert their opponents.

A look at this same data summarised by era suggests that all three of these proportions are trending upwards though, to this point, 2012 is not perpetuating that trend.