On The ICC's Pitch Evaluation System

Note: This is an old essay which I prepared in 2018. Its reports on the pitch monitoring system introduced by ICC in 2018. It was originally published on the thREAD collaborative blog at The Hindu. Based on this, what do you think of the pitches for the three Tests in this series?

The pitch is central to the shape of a Test match. Over 5 days, pitches change character sufficiently to bring different skills to the fore. Traditionally, it has been the host cricket board’s privilege to prepare the pitch for any Test match. The Laws of Cricket only specify that the game not be played on a pitch which umpires might consider to be dangerous to the health of the players. The ICC has chosen to go beyond this elementary classification between dangerous and non-dangerous pitches by setting up a regulatory mechanism which is designed to minimize the probability that a bad pitch (and not just a dangerous pitch) will be prepared. This regulatory expansion is worth examining in greater detail because it specifies what the ICC considers to be a “bad” pitch.

Every pitch and every outfield used in an international Test, ODI or T20 match is rated according to newly specified criteria(pdf). The new rating system includes six categories - “very good”, “good”, “average”, “below average”, “poor”, “unfit”. Each pitch and outfield is assigned one of these six categories at the end of each game. Demerit points are allocated for below average (1), poor (3) and unfit (5) pitches. Poor outfields receive 2 demerit point. Unfit outfields receive 5 demerit points. Demerit points remain active for 5 year rolling period. Any ground which accrues 5 demerit points is suspended from international competition for 12 months. A ground which accrues 10 demerit points is suspended for 24 months. The total demerit points allocated to a ground for a game is the larger number in the (pitch, outfield) tuple. For instance, a below average pitch and a poor outfield will earn a ground 2 demerit points (the greater number out of 1 for the below average pitch and 2 for the poor outfield).

The category of a pitch and an outfield is determined by the match referee based on a standardized record to be maintained as the game progresses. This standardized record comprises of 10 questions which are designed to be answered from the beginning of the match to the end. The final two questions require the referee to categorize the pitch at the end of the match based on the record built in the first eight questions.

To understand how (and to what extent), the answer to question 9 and 10 is determined by the observations recorded in the first eight questions, the ICC’s definitions of each category of a pitch must be consulted.

A “very good” pitch is one with “[g]ood carry, limited seam movement and consistent good bounce early in the match and as the pitch wears as the match progresses, with an acceptable amount of turn on the first two days but natural wear sufficient to be responsive to spin later in the game.”

A “good” pitch is one with “[a]verage carry, moderate seam movement and consistent bounce both early in the match and as the pitch wears as the match progresses, natural wear sufficient to be responsive to spin from day 1, though not quite meeting the criteria for carry and bounce for a “very good” pitch.”

An “average” pitch is one which “[l]acks carry, and/or bounce and/or occasional seam movement, but consistent in carry and bounce. A degree of turn, but with average bounce for the spinner. Falling significantly short of “very good” with respect to carry, bounce and turn.”

A “below average” pitch is one with “[e]ither very little carry and/or bounce and/or more than occasional seam movement, or occasional variable (but not excessive or dangerous) bounce and/or occasional variable carry. If a pitch demonstrates these features, then the pitch cannot be rated in a higher category regardless of the amount of turn the pitch displays at any stage of the match.”

A “poor” pitch is one which “does not allow an even contest between bat and ball, either by favouring the batters too much, and not giving the bowlers (seam and spin) from either team sufficient opportunity to take wickets, or by favouring the bowlers too much (seam or spin), and not giving the batters from either team the opportunity to make runs.”

Further, a pitch may be rated as “poor” if any one of the following criteria apply:

• The pitch offers excessive seam movement at any stage of the match

• The pitch displays excessive unevenness of bounce for any bowler at any stage of the match

• The pitch offers excessive assistance to spin bowlers, especially early in the match

• The pitch displays little or no seam movement or turn at any stage in the match together with no significant bounce or carry, thereby depriving the bowlers of a fair contest between bat and ball.

The ICC’s view of a good pitch seems can be broken down easily. If we consider that two types of variation are essentially possible - lateral variation, where the ball moves towards off or leg, and vertical variation, where the ball bounces higher and lower than normal (note, this is not some general normal, but the normal specific to the pitch), then the ICC is far less forgiving of vertical variation in bounce than it is of lateral variation. Some lateral variation could indeed be considered desirable. The role of the referee is to test when this lateral variation becomes excessive. This is a judgment call, but it helps that referees are typically experienced former international cricketers from across the cricket world (and not just the subcontinent, or the southern hemisphere). But their job is simplified by the fact that the existence of variable bounce on Day 1 means that under the definitions specified by the ICC, the pitch must be either “below average” or “unfit”.

Variable bounce can (and typically does) develop as a match progresses. The speed and extent of deterioration determines the conclusion about the pitch. For example, the analysts at CricViz reported that at Wanderers, after three innings, 28 balls hit the batsman on the glove. In all Tests in 2017, 10.85 balls hit the batsman on the glove in one Test, on average. 90844 balls were bowled in 47 Tests in 2017. Overall, in 2017, one ball in 178 hit the batsman on the glove.

CricViz provided me with a day wise break down of balls hitting the batsman on the glove for each Test of India’s series in South Africa. Over the first two Tests of the series, one ball in 165 hit the batsmen on the glove. In the third Test, one ball in 52 hit the batsman on the glove. Further, the frequency of batsmen being hit on the glove deteriorated sharply during the Test. On the third day, which was the worst, one ball in 27 hit the batsman on the glove.

It is worth keeping in mind what the ‘gloved’ measurement records. Batsmen do not like to be hit on the gloves. They prefer to play the ball with the bat. Failing this, they prefer to miss the ball. The fact that the batsman is being hit on the glove suggests that they the ball misbehaved in a way which gave the batsman no chance to avoid getting hit. The gloved statistic is a conservative estimate of misbehaviour. Not all deliveries which misbehave and give the batsman no chance to adjust hit the batsman on the glove. Some may hit the batsman on other parts of the body. Still others may miss the batsman entirely. But there’s no reason to think that in some instances of variable bounce, the ball hitting the glove might be an especially unusual event.

It is clear, based on the judgment of the umpires towards the end of Day 3, the use of the heavy roller to settle the pitch at the beginning of the Day 4, and the unusual view of Dean Elgar (who carried his bat in the 4th innings) that the match should have been called off due to the state of the pitch, that the Wanderers pitch was, at the very least, unusual. Given the ICC regulations about being unforgiving about uneven bounce and excessive seam movement, the “poor” rating given to the Wanderers pitch is, at the very least, correct application of the regulation.

Given ball-tracking data which provides information about bounce, turn and seam movement, the ICC could easily regularize this pitch regulation system and make the job of the match referee significantly easier. Currently, referees are required to exercise judgment about the nature of the bounce, turn, movement and misbehaviour. These things are easily measurable from ball-tracking information. The natural next step would be to use ball-tracking data to evaluate the performance of the pitch.

The ICC’s system for regulating pitches still has one serious omission. This omission is no oversight. It exists by design. The ICC is not responsible for the preparation of pitches. It is a regulator. It evaluates pitches based on cricket played on them. The art of pitch preparation is left entirely to the host board. The ICC could specify a standardized method for preparation of turf pitches, and then monitor whether these standardized methods are being followed. This would arguably be fairer to the ground. For instance, excessively inclement weather in the lead up to a game can adversely affect pitch preparation. Resultant pitches can be underprepared and fall foul of the ICC’s regulations. Should a ground where a pitch was unfit due to extenuating circumstances be penalized in the same way ground where there were no extenuating circumstances? Currently, the ICC’s view seems to be that the distinction is irrelevant. But since the penalty is denial of games for 12 months, perhaps the distinction is significant, because it materially affects the likelihood that bad pitches will be prepared in the future at this venue.

The use of ball-tracking data would make the ICC’s current regulatory regime more precise. The development of a pitch preparation best-practices manual would make this regulatory regime less blunt as an instrument for governing the preparation of pitches in international cricket. As it currently stands, this evaluation system goes far beyond what the laws of cricket specify about acceptable pitches. On balance, given the necessity of ensuring that games provide for a wide-ranging demonstration of skills, and the strong compulsions which often drive host boards when it comes to preparing pitches (pressure to win at home, pressure from the home team), these new regulations are unavoidable.