22. Player Improvement

Looking at cumulative career averages and strike rates can give interesting insights on a player's career

Conventionally, we look at cricket statistics as “point statistics”. Batting and bowling averages, for example, are treated as static numbers, with a single number being used to describe a player’s entire career. Sometimes we look at series averages. Sometimes, data mining exercises lead us to looking at averages across certain specific cuts.

However, if we start looking at statistics as a time series, we can use that to tell far more interesting stories. For example, yesterday India dropped Kedar Jadhav for the game against Bangladesh. At the outset, this looks like a silly decision since Jadhav averages overs 40 and has a strike rate over 100 in ODIs.

However, if we look at Jadhav’s career trajectory, it becomes clear that he is a player in decline, with both his average and strike rate having declined from their peaks in mid-2017.

In fact, if we look at similar average and strike rate trajectories for some of the prominent batsmen playing in the ongoing World Cup, we can construct elaborate stories of their careers. Much has been made, for example, of Hashim Amla and Virat Kohli being close together in the number of innings they took to hit 8000 ODI runs. If we look at their career trajectories, however, they are very different players.

Kohli is a player who has been on a steep ascent at least for the last three years, both in terms of his average and strike rate. On the other hand, Amla’s career is in decline, with his career average having come down to just below 50 and his strike rate also having declined.

We can look at these cumulative career graphs for other players and they will throw up other interesting stories. Here are the cumulative career average graphs for the 20 most experienced top order (1-6) batsmen at the ongoing World Cup.

Some players’ careers are a study in constant improvement, such as Rohit Sharma or Tamim Iqbal. Mushfiqur Rahim, Ross Taylor and Faf du Plessis are also going through periods where they continue to improve. Shakib Al Hasan’s batting average had declined and stagnated around 35 for several years, but now we see that his spectacular World Cup has resulted in a spike in average at the very end.

Mohammad Hafeez has had a very interesting career as well. The periods when he was averaging less than 20 and dropped from the team are easily visible on this graph. Also clear is his rapid improvement after he made his comeback in 2011, after which he has become a mainstay in Pakistan’s lineup.

There are interesting stories to be found in cumulative career strike rates as well. And here, we need to remember that overall scoring rates have increased over time, so you would expect career strike rates for batsmen to also marginally improve over time. Instead we see that Amla, MS Dhoni, Kane Williamson and Tamim Iqbal have all been batting slower as their career has progressed.

For the sake of completeness, I’ll leave you with cumulative bowling average and economy rate graphs for the 20 most experienced bowlers at the World Cup as well. Notice how Mohammad Hafeez’s bowling economy also improved dramatically at the same time as his batting.