Gulf in the BPL

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The aim was to post this article halfway through the 2017 BPL season. Then time started passing much quicker than usual and I was resigned to wait until next year. But there was also no guarantee that the BPL would still exist next year. T20 competitions have a startling tendency to suddenly disappear

Re-motivated, I now start writing in the hope that this article will at least be online before the competition finishes. Given that I have only just watched Johnson Charles and Brendon McCullum propel the Rangpur Riders into the final today… finishing before the end (i.e. tomorrow) might be optimistic. I'll give it a go

The qualifier presented a stark contrast between overseas contributions from each team. The Rangpur innings depended entirely on a trio of international superstars who scored every run. Comilla, meanwhile, relied on three lesser-known domestic players to keep the game competitive before their internationals entered the game and promptly ruined everything

I’m not the first person to notice the imbalance between overseas and domestic players in the BPL. It isn't hard to spot. The evidence was already clear with just eight games gone, Dan Weston suggesting that teams willing to start five overseas batsmen would have a significant advantage

With the tournament almost over, the chasm between overseas and domestic players has remained. The overseas players are far more productive than their Bangladeshi equivalents. Interestingly, the overseas batsmen are consistent against both overseas and domestic bowling. In contrast, the overseas bowlers prey disproportionately on the domestic players to exhibit their superiority

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Chart showing the discrepency and talent gulf between overseas and domestic batsmen and between overseas and domestic bowlers, depedning on the matchups

This phenomenon is not exclusive to the BPL. Touring internationals are often better players than their latest set of teammates. The chart below compares leagues across the world based on the disparity between local and overseas players

Both axes record Runs Added per ball, a metric that combines batting average and strike rate into one statistic that is also sensitive to match situation. Players who improve their teams projected total by protecting their wicket and scoring at a faster than the expected rate accrue positive Runs Added. Players who hurt their teams chances accrue negative Runs Added

The diagonal line marks the points where domestic talent equals their overseas counterparts. The IPL, PSL, CPL and T20 Blast all lie close to the line - overseas and domestic batting performances are well matched. This may highlight a strong pool of local talent or relatively weaker internationals, depending on the league

Comparison of leagues based on the disparity between local and overseas players

But the BPL stands out as owning a particularly cavernous gap between overseas and domestic play. And it has been getting worse over time. That gap was not as large when the competition first started in 2012 

This is partly a symptom of the BPL’s success. As the league has grown, it has been able to attract ever more high profile stars. Present day, the five top scoring international players are: Evin Lewis, Ravi Bopara, Chris Gayle, Luke Ronchi, and Andre Fletcher. In 2012, those names were: ten Doeschate, Brad Hodge, Brendon Taylor, Paul Stirling, and Azhar Mahmood. The league has gone from being an opportunity for associate players to acquire overseas experience to an opportunity that can genuinely boost prospects of an IPL contract

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I'm already bored of writing the words 'overseas' and 'domestic'. From here on, I am going to generalise horrendously and call every overseas batsman Luke Ronchi and every domestic batsman Tamim Iqbal. And I shall call overseas bowlers Jofra Archer. Domestic bowlers aren't featured in the analysis again

Let's hope its not too confusing...

The idea that teams should favour Luke Ronchis in preference to Jofra Archers makes a lot of sense. And it doesn’t entirely depend on the gulf between batsmen being wider than the gulf between bowlers. The Rangpur Riders demonstrated that one or two Luke Ronchis can dominate an entire innings. The influence of a single Jofra Archer is limited by the fact that he can only bowl four overs

I think this Ronchi thing is working...

However, I also had a hypothesis that such disparities could benefit the bowling side more. From a game theory perspective, they have the advantage that they can see the opponents hand. They know which batsmen are at the crease and, therefore, which bowler is best suited for the task

Perhaps counter-intuitively, the data suggest that teams should be using their Archers to attack the weaker Iqbals in the other team. We saw that it doesn't seem to matter to Ronchis which type of bowler they face whereas the Iqbals are especially prone to overseas bowling. But BPL teams don't take advantage. They utilise Archers with identical frequency, regardless of who is at the crease. Both Ronchis and Iqbals received 43% of balls faced from Archers

Maybe I am not being fair to the bowling team. After all, the batting team can also exert a tiny amount of control over matchups. By rotating the strike or targeting boundaries as appropriate, the batting pair can influence which batsman stands on strike...

56% of the time, the pair in middle was a partnership between Ronchis and Iqbals (rather than two of the same type). As always, Luke Ronchi tends to score faster (128 SR) than Tamim Iqbal (114 SR). Inexplicably, he also faces slightly fewer balls (48%). He is either failing to keep strike or neglecting to do so. I feel like at least one of the bowling or batting sides must be missing an opportunity here!

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Having said that, it is probably worth reflecting that I am searching for relatively minor gains here. Larger gains are in plain sight

Against Rangpur’s bowling today, and chasing a huge target, the domestic players at the top of the order did a great job keeping the Comilla Victorians in the chase (and one of them actually was Tamim Iqbal). The score was 57/2 by the end of the Powerplay, the run rate only a shade under what was needed

Then Marlon Samuels produced the absolute worst innings that my short memory can recall. Between the 10th and 18th overs, he faced 30 balls and scored precisely 21 fewer runs than needed to match the opposition run rate – 21 !

If we are being honest, you don't always need the absolute perfect strategy to win a match

Just don’t do what Marlon Samuels did... it can't be that hard