Muttiah Muralitharan: on top of the charts © AFP

The post on "Bowler Consistency" received many comments, some silly, some sceptical, some dismissive, some appreciative and some happy at the thinking process it initiated. There were many relevant comments, which warrant a follow-up post.

First of all, an apology to the readers. I used "spell" when I really meant "innings spell". A spell is an uninterrupted stint of bowling. What I really meant was the bowling done during an innings. So I have coined an alternate term called "innspell" which is exactly what it means, the complete bowling effort during an innings, often consisting of multiple spells. Many thanks to the readers who took me to task on this issue.

There were many relevant comments on bowler strike-rates and other pertinent measures such as bowling support, pressure situations, bowling accuracy etc. I do not want to mix up the criteria. Bowler strike-rate is not to be confused with the ability of bowlers to be more consistent. That is one of the most important of bowler measures and warrants a separate post. A similar situation exists with the other measures as well.

I am also determined that I will keep the analysis as simple as when the post started. Finally, one factor should not be forgotten: what I have stated is that if a spin bowler bowls 11 overs or above and takes at least a wicket, this innspell is considered to be a success as compared to a bowler who bowls a similar innspell and comes out wicketless. There is nothing fundamentally wrong with this statement.

However the one comment which also impressed me a lot was the suggestion to reward bowlers for taking more than one wicket in an innsspell. Hence I have added a simple linear weightage factor to a successful innsspell. For each wicket captured, a weightage of 10% is given. Thus a 1-wkt capture makes this value as 1.1, 2-wkt capture as 1.2 and so on upto the two 10-wicket captures of Laker and Kumble as 2.0. This tweak should satisfy most readers. The Bowler Consistency Index value is computed as a % of "number of relevant spells x 2.0".

Readers will note that this method will increase the consistency ratings of bowlers who have captured more wickets in their career. An alternative would have been to consider a one-wickett haul to have a value of 1.0 and anything more as 1.1. This would still have left the disparity between insspells which fetched two wickets, and those that fetched more than two.

The most significant comment was that 30 innspells are not sufficient. The lowering of the bar has allowed quite a few relatively insignificant bowlers to walk through at the expense of bowlers who have served for longer periods. Hence I have raised the bar, and considered only the bowlers who have bowled a minimum of 50 innspells, which translates to around 30 Tests, possibly 4-5 years of Test cricket. A total of 143 bowlers have qualified under this criteria compared to 276 bowlers with the lower cut-off.

There were a few (mostly unwarranted) comments on Mervyn Dillon. He has taken 131 wickets in 38 Tests, not a bad haul. Just taking a "wickets per Test" criterion, he is ahead of more well-known bowlers such as Derek Underwood, Kapil Dev, Vaas, Zaheer Khan, Daniel Vettori, Sarfraz Nawaz, Michael Kasprowicz and S Venkataraghavan. Comments should be made only after verifying facts and making allowance for his playing in a weak West Indies team all his career.

The revised table is given below.

Bowler Consistency Analysis (Revised with weightage) - Min 50 relevant spells

                                    <----Innspells---->

SNo Bowler            Bow Ctry  Mat Relevant Successful BCIdx  Wkts Wkt/IS

                                               Total

  1.Muralitharan M    ROB  Slk  118    201     267.3    66.49   723  3.60

  2.Grimmett C.V      RLB  Aus   37     66      84.6    64.09   216  3.27

  3.Kumble A          RLB  Ind  125    215     262.4    61.02   604  2.81

  4.Hadlee R.J        RFM  Nzl   86    138     168.1    60.91   431  3.12

  5.Bedi B.S          LSP  Ind   67    107     129.6    60.56   266  2.49

  6.Warne S.K         RLB  Aus  145    250     302.8    60.56   708  2.83

  7.Donald A.A        RF   Saf   72    124     150.0    60.48   330  2.66

  8.Trueman F.S       RF   Eng   67    115     138.7    60.30   307  2.67

  9.Lillee D.K        RF   Aus   70    124     149.5    60.28   355  2.86

 10.Gupte S.P         RLB  Ind   36     54      64.9    60.09   149  2.76

 11.Dillon M          RFM  Win   38     55      66.1    60.09   131  2.38

 12.Imran Khan        RF   Pak   88    125     150.2    60.08   362  2.90

 13.MacGill S.C.G     RLB  Aus   42     76      91.3    60.07   203  2.67

 14.Wasim Akram       LFM  Pak  104    161     192.4    59.75   414  2.57

 15.Danish Kaneria    RLB  Pak   51     84     100.0    59.52   220  2.62

 16.Croft C.E.H       RF   Win   27     50      59.5    59.50   125  2.50

 17.Chandrasekhar B.S RLB  Ind   58     87     103.2    59.31   242  2.78

 18.Saqlain Mushtaq   ROB  Pak   49     78      91.8    58.85   208  2.67

 19.Gough D           RF   Eng   58     91     106.9    58.74   229  2.52

 20.Laker J.C         ROB  Eng   46     77      90.3    58.64   193  2.51

 21.Trumble H         ROB  Aus   32     53      62.1    58.58   141  2.66

 22.Ambrose C.E.L     RF   Win   98    164     191.5    58.38   405  2.47

 23.Marshall M.D      RF   Win   81    147     171.6    58.37   376  2.56

 24.Bishop I.R        RF   Win   43     67      78.1    58.28   161  2.40

 25.Cork D.G          RFM  Eng   37     57      66.1    57.98   131  2.30

(Click here for the full table.)

Muralitharan is on top, followed by Grimmett, Kumble, Hadlee and Bedi. This is not a bad quintet. The next five bowlers are Warne, Donald, Trueman, Lillee and Subash Gupte. There should be no complaints there either. The top 25 table now includes most bowling stalwarts, which should satisfy most readers. The weightage of values and raising the cut-off bar has taken away most of the lesser, shorter-duration bowlers.

I have added another variable, the average wickets per innspell, which is indicative of the bowler performance. Muralitharan is way ahead of the other bowlers, having taken 3.6 wickets per innspell. Compare the numbers for some of the other greats. Donald - 2.66, Kumble - 2.81, Pollock - 2.30, Warne - 2.83, Lillee - 2.86 and Ambrose - 2.47. It shows what a wonderful wicket-taking bowler Muralitharan is, even if you concede that the bowler at the other end was not always competing with him in taking wickets. Note also that Flintoff is the only bowler in the top-50 whose wickets per innsspell figure is less than two.

The unfortunate aspect of increasing the cut-off is that this has excluded the pre-World War I all-time greats such as Sydney Barnes, George Lohmann etc. In order to be fair to these great bowlers I have given below a list of five such pre-WW I bowlers.

Barnes S.F          RFM  Eng   27     48     64.9     67.60   189  3.94

Lohmann G.A         RFM  Eng   18     32     40.2     62.81   112  3.50

Giffen G            ROB  Aus   31     35     43.3     61.86   103  2.94

Briggs J            LSP  Eng   33     42     51.8     61.67   118  2.81

Blythe C            LSP  Eng   19     35     43.0     61.43   100  2.86

Look at Barnes' wickets per innspell figure - it is higher than Muralitharan's.

	Shane Bond has never gone wicketless in an innings in Test cricket © Getty Images

The batsmen tend to get analysed lot more and it is now the turn of Test bowlers. Two not-so-normal measures will be discussed in the next two posts.

Bowler consistency

How does one measure a Test bowler's consistency. Complex statistical measures will neither indicate the real consistency nor be understood by all. If I pepper this article with words such as Sigma, Skew, Mean deviation or Variance, I would have lost more than half the readers. What is needed is a cricketing definition of consistency and a simple easy-to-understand methodology which will be understood by all readers.

What makes a consistent bowler? The answer is easy: one who bowls good spells most of the time. How does one define a good spell? There are many definitions, most of which would be too subjective. The only objective measure we have is the "wickets captured" information. The importance of taking wickets in Test matches is also incorporated in this computation.

Taking the 1860-plus Tests which have been played so far, on an average a pace bowler takes a wicket every 66 balls, while the strike-rate for a spinner is 80 balls. At the two extremes are George Lohmann, with a strike-rate of 34, and Carl Hooper with a strike-rate (if you can define it thus) of 120. Taking all these factors into consideration, I have taken 66 balls in an innings for the pace bowlers and 78 balls for spinners as base figures to determine whether a bowler has bowled a relevant spell or not.

First we determine the number of relevant spells, which is defined as an innings in which a bowler has - depending on whether he is a spinner or a fast bowler - bowled at least 78 or 66 balls, or an innings in which the bowler has captured a wicket or more. Then we determine the number of successful spells - the bowling stints in which the bowler has taken at least one wicket. We then derive the Bowler Consistency Index. In ODIs, a wicketless spell, such as Kapil Dev's 7.0-4-4-0 against West Indies could be an outstanding one because of the economy factor, but not in Tests. A bowler such as Bapu Nadkarni in 1964 in Chennai with a spell of 32-27-5-0 would today be booed off, as also Ken Barrington and Brian Bolus, the immobile batsmen.

Let us see the table. These are current upto the fourth test between Australia and India in Adelaide.

Bowler Consistency Analysis - Min 30 spells

No Bowler           Bow Team  Mat  <------Spells-----> Consistency

                                   Relevant Successful    Index

 1. Bond S.E        RFM  Nzl   17      30      30         100.00

 2. Jones S.P       RFM  Eng   18      30      30         100.00

 3. Reid B.A        LFM  Aus   27      39      38          97.44

 4. Muralitharan M  ROB  Slk  118     201     195          97.01

 5. Miller C.R      ROB  Aus   18      30      29          96.67

 6. Dillon M        RFM  Win   38      55      53          96.36

 7. Bedi B.S        LSP  Ind   67     107     103          96.26

 8. Barnes S.F      RFM  Eng   27      48      46          95.83

 9. Grimmett C.V    RLB  Aus   37      66      63          95.45

10. Briggs J        LSP  Eng   33      42      40          95.24

11. Adcock N.A.T    RF   Saf   26      41      39          95.12

12. Donald A.A      RF   Saf   72     124     117          94.35

13. Blythe C        LSP  Eng   19      35      33          94.29

14. Giffen G        ROB  Aus   31      35      33          94.29

15. Vincent C.L     LSP  Saf   25      35      33          94.29

16. Flintoff A      RFM  Eng   67     101      95          94.06

17. Croft C.E.H     RF   Win   27      50      47          94.00

18. Kumble A        RLB  Ind  125     215     202          93.95

19. Lever J.K       LFM  Eng   21      33      31          93.94

20. Trueman F.S     RF   Eng   67     115     108          93.91

21. Wasim Akram     LFM  Pak  104     161     151          93.79

22. Steyn D.W       RFM  Saf   18      32      30          93.75

23. Tauseef Ahmed   ROB  Pak   34      47      44          93.62

24. Robins R.W.V    RLB  Eng   19      31      29          93.55

25. MacGill S.C.G   RLB  Aus   42      76      71          93.42

(Click here for the full table.)

The two injury-prone speedsters Shane Bond and Simon Jones have bowled 30 successful spells in their career, a 100% record. In fact Bond has the unique distinction of never having gone wicketless in an innings in his entire career: his three sub-11-over spells have also been fruitful. Muralitharan has bowled over 200 spells and has gone wicketless in only six of these, which is the very definition of consistency. Then we have a few vintage greats. Bishan Bedi Allan Donald are in the top 15. Andrew Flintoff, Anil Kumble, Wasim Akram and Stuart MacGill are in the top 25.

Note the very high degree of consistency of otherwise pedestrian bowlers like Mervyn Dillon, Colin Miller and Tauseef Ahmed.

Just as a matter of interest, the last five bowlers in this group are listed below. The last two places are filled, as expected, by one part-timer from West Indies, known more for his batting prowess, and an Australian spinner of limited skills.

Julien B.D         LSP  Win   24    40     27      67.50  

Mackay K.D         RFM  Aus   37    39     26      66.67  

Whittall G.J       RFM  Zim   46    38     25      65.79  

Hooper             ROB  Win  102    99     64      64.65

Bright             SLA  Aus   25    31     20      64.52

The six unsuccessful spells of Muralitharan are given below. Note the long gap between such rare instances, especially between 1999 and 2006, when he went 55 Tests without missing out even once.

1306  1995  Pak    17.0  3  53 0

1358  1997  Nzl    33.0  6 136 0

1387  1997  Ind    46.0  9 137 0

1416  1998  Nzl    23.0  9  33 0

1474  1999  Zim    24.0  6  51 0

and after 7 years

1796  2006  Pak    13.0  3  46 0

In view of the number of comments made, I have tried to answer these in the blog itself.

1. This is only an "invented" common-sense based analysis. Do not read more into this than that.

2. If we do a list of triple-centurions, we will have Lawrence Rowe, Bob Cowper and John Edrich in that list. We will not have Tendulkar, Dravid, Ponting and Richards there. Does it make them any less greater batsmen. Take this list like that.

3. Maybe 30 spells is too low. It shoud be increased to 50 spells. However I could not resist the temptation to include Bond (for his pure career).

4.What I have written here is a simple definition of consistency which is totally different to strike rate or bowling average or bowling accuracy. If a batsman scores 100 and 0, and another batsman scores 40 and 40, the later would be considered more consistent while the former's average would be higher. Similarly a bowler who has captured 20 wickets in 5 tests at the rate of 4 wickets per test would be considered more consistent than one who captures 8, 0, 8, 0, and 8 wickets even though the later might have captured more wickets at possibly better strike rate.

5. I have used "spell" to denote the bowling effort during an innings for want of a suitable word. A more apt word might be "Innings analysis".

6. The next blog will answer some of the questions raised.

7. A full list of qualifying bowlers will be made available shortly so that readers can check all the bowlers themselves. The list has been mailed individually to readers whose comments indicated a need to look at such a list.