Wherever we have sports, we have stats. Many actions in a sport can be quantified. Players are often defined by the numbers they generate. The greatest players often have the most glittering collection of stats against their names. Even in this number laden world, one statistic towers above all – Sir Donald Bradman’s batting average of 99.94 in the sport of Test cricket.
Over the ages, legendary sportsmen have churned out extraordinary performances and have accumulated staggering numbers. But here we will try to justify why the legendary Australian’s feat is often heralded as one of the greatest achievement for any sportsman in a major sport.
Why is Batting Average so important in cricket
Cricket is all about scoring more runs than the opposition. Batsmen need to score as many runs as possible in an innings and the fielding team needs to limit the scoring. So players who can make tons of runs are the stars of any team. Cricket has multiple formats, but the five day game of Test cricket is the oldest and arguably one that requires the most skill.
It has been widely accepted that batting average is the most accurate among the stats that we have in order to judge a batsman’s consistency. Batting average denotes how many runs a player scores per inning on average. It can be calculated for any period of time during a batsman’s career. And to illustrate Bradman’s remarkable achievement, we use a statistical diagram called a box plot to compare his batting average to his peers’.
What the boxplots reveal
When players are compared, it is often debated about how the game has changed over the years and so it is unfair to compare two players from different eras. Every era has had differences in playing surfaces, quality of opponents, and pressure from the audience etc. But there is a way in which players can be analyzed. This way is by comparing the dominance a player exerted over his contemporaries. So for this analysis, we decided to compare players from a similar timeframe so as to greatly reduce era bias in the numbers.
We picked three eras – 1925-50, 1965-90, 1991-2013 and obtained the batting averages for each of these eras1. When we plotted the averages as points in a box plot format, we got these results –
The grey box represents 50 percent of the data with 25% on each side of the middle line which is the median2 of the data. These 25 % areas are called ‘quartiles’. The top and bottom tails represent the rest of the data.
A box plot is a good way to see how data is distributed and represents it’s variance. The lengths of the box and the tails and the position of the median line tell us about how skewed the data is. If the median line is near the top that means there is less variance in the top data and vice versa. Similarly if the top tail is smaller it means there’s less variance in top data and vice versa.
In this case, you can see that the batting averages in the last two eras are quite identically distributed. But in the era 1925-50, you can see that there is a point at the top which is far away from the box plot. This point represents Bradman’s average of 99.94.
Bradman – A batsman like no other
This diagram not only reflects Bradman’s staggering dominance over his contemporaries, but it also illustrates how far away from the pack Bradman was as compared to dominating players from other eras.
Such was Bradman’s influence on his rivals that in 1932-33, the England team devised a whole new negative bowling technique called ‘Bodyline’3 specifically to combat Bradman’s extraordinary batting skills.
More than the numbers, this is a fitting tribute to his abilities. To put it simply, no other player has dominated his age like Bradman has.