Tuesday, March 13, 2012

The DRS should Eliminate Howlers. And Those Alone

By Vineet Goyal

Much has been written and debated about the effectiveness of DRS and it is fair to say that the jury is still out. Recent comments from Jacques Kallis are a good indication that the majority of players are not entirely comfortable with the system. However, most agree it is quite effective in eliminating blatant errors and the game is better off with some sort of DRS in place. Eliminating howlers was in fact the primary intended purpose of the system. So why is there still opposition to the system if it serves its primary intended purpose so well.

The answer lies in not what it does but in what it does not do effectively. It is completely ineffective in marginal decisions – the current technology used in DRS especially for predicting the trajectory of the ball in an lbw decision is not accurate enough for players and administrators to feel confident. But marginal decisions! No one was worried about those anyway – at least not the players. All we wanted was to eliminate the howlers for which DRS seems to work quite well. The problem however is that once the system is in place, we cannot ask the players to use it only in cases of a howler. The players realize that the technological shortcomings of the system can be exploited and therefore, they can use the DRS strategically to get a decision in their favor. This is very discomforting from everyone’s perspective.

The objective of DRS should instead be to eliminate howlers and just that. It would be futile to formally define a howler but in principle from the perspective of the batsman, we can think of a howler as a decision where the batsman feels (in his mind) that grave injustice has been done to him in giving him out. Now, an lbw decision where the ball was perhaps just hitting the top of middle stump is not a howler (assuming there was no inside edge and impact was inside the line of stumps) – in this case, a batsman would be disappointed but in his heart knows that he was beaten and perhaps out. Clearly, we cannot have a system where by rule the players can ask for a review only in case of a howler. This should happen by design. Here is a proposal that I feel should achieve this:

1. The batting team is allowed only ONE unsuccessful review for both the innings.
2. The bowling team is allowed two unsuccessful reviews per inning as in the current system.

The asymmetry in batting and bowling reviews is because of the asymmetry in knowledge between batsman and bowler. The batsman knows whether he nicked the ball almost surely but the bowler may not.

So lets see how this system would play out. A batsman will review only if he is absolutely sure that he is not out. Except lbw decisions, the batsman knows whether he is out or not. Anyone who has played cricket would know that you feel the vibrations from the faintest of nicks and you know it. If the batsman didn’t edge the ball and is given out, the review will certainly reverse the decision – none of the technologies including hot-spot and snicko give a false positive. So non-lbw decisions will be ruled correctly.

It is a bit more trickier for the lbw decisions because the batsman does not know whether the ball was going to hit the stumps or even whether the impact was in line or not. It’s amazing to see the performance of umpires on the elite panel currently – even the players would testify that the umpires are extremely accurate about things like estimated path of the ball and line of impact. Of course, they are humans and making real-time decisions, so they are bound to make marginal errors of a millimeter here and there. And I think the players are ok with such errors. If Kallis is beaten to an incoming delivery that is crashing onto the middle stump and hits him a millimeter outside the off-stump, I don’t think he will feel cheated if he is given out. The howlers in lbw decisions happen (at least these days) when batsman are given out after an inside edge which is easy for batsman to detect and then review. But since batsmen have only one unsuccessful review for two innings, they will not review marginal decisions.

What about the bowling team? Can they use it for marginal decisions? Since there are two unsuccessful reviews allowed, they might like it happens in the current system. However, this should not be a problem. This system does not produce false positives, i.e., if the batsman did not edge, there will be no hot-spot. So if the batsman is indeed not out, the system would rarely reverse the on-field not-out call. However, in case of a blatant error, the decision is reversed. Therefore, the DRS essentially comes into play only in blatant errors and has no impact in marginal decisions.