July 16, 2012

Developing a bowling value index

An analysis to develop a bowling index to help measure the value of Test bowlers

While looking back statistically over the career of the recently-retired Brett Lee, I mused over ways of assessing the value of bowlers to their team. Lee, of course, was a fast bowler best used in short spells, and was not one who one would use to plug up an end and bowl all day. He thus had quite a good strike rate (10th in the list of 35 Test bowlers with 250 wickets or more), but for limited times of the playing day only. He only bowled 21.25% of the balls bowled while his team was fielding, ranking him only 25th in the same list of 35 bowlers. Obviously, his value to his team would have been enhanced if could have bowled more while preserving his strike rate - but there is a risk, of course, that the strike rate diminishes if a bowler is asked to bowl more.

I am thus inching towards a statistical measure of the value of a bowler, V, that is a function of Strike Rate (balls per wicket), i.e., V = k(SR)

where k is a constant representing the amount of bowling a bowler does.

The simplest way to calculate this is to divide the proportion of overs that each bowler bowls for his team by the strike rate. Thus for Lee, V = 21.25/53.33 = 0.398

The table below displays the value of V for each of the 35 bowlers with 250 Test wickets or more:

* % tbb represents percentage of teams balls bowled by the bowler

 Player Wickets SR % tbb V Muttiah Muralitharan 800 55.05 33.31 0.605 Dale Steyn 272 40.94 21.73 0.531 Richard Hadlee 431 50.85 24.86 0.489 Shane Warne 708 57.49 28.00 0.487 Waqar Younis 373 43.50 21.09 0.485 Dennis Lillee 355 52.02 25.19 0.484 Malcolm Marshall 376 46.77 22.62 0.484 Glenn McGrath 563 51.95 24.36 0.469 Joel Garner 259 50.87 23.41 0.460 Allan Donald 330 47.03 21.50 0.457 Anil Kumble 619 66.00 28.77 0.436 Wasim Akram 414 54.65 23.58 0.431 Danish Kaneria 261 67.80 29.06 0.429 Fred Trueman 307 49.44 21.11 0.427 Curtly Ambrose 405 54.58 23.17 0.425 Imran Khan 362 53.75 21.88 0.407 Courtney Walsh 519 57.84 23.18 0.401 Brett Lee 310 53.33 21.25 0.398 Harbhajan Singh 406 68.11 27.09 0.398 Craig McDermott 291 57.00 22.34 0.392 Shaun Pollock 421 57.85 22.47 0.388 James Anderson 267 57.29 22.02 0.384 Makhaya Ntini 390 53.42 20.50 0.384 Jason Gillespie 259 54.96 20.63 0.375 Ian Botham 383 56.96 21.29 0.374 Bob Willis 325 53.41 18.66 0.349 Bishen Singh Bedi 266 80.32 27.75 0.345 Zaheer Khan 288 58.05 19.09 0.329 Brian Statham 252 63.71 20.77 0.326 Daniel Vettori 359 78.98 25.59 0.324 Derek Underwood 297 73.61 23.85 0.324 Chaminda Vaas 355 66.02 20.71 0.314 Kapil Dev 434 63.92 20.05 0.314 Lance Gibbs 309 87.75 26.85 0.306 Jacques Kallis 276 68.67 12.64 0.184

Murali was clearly, under this measure, the most valuable bowling commodity to his team in Tests - not only does he possess a strike rate more in tune with that of strike fast bowlers (compare it with Kumble, Bedi and Vettori, for example), but he bowled an extraordinarily high percentage of Sri Lanka's overs in Tests in which he took part, bowling one over in three.

It would appear, too, that Dale Steyn is forging a career that will put his name up in lights alongside the great bowlers of yesteryear. No one can question Hadlee's high index, given his value to an otherwise unexceptional New Zealand team, while the high positions held by Warne and McGrath formed the basis of Australia's period of domination in the first decade of this century. Similarly, Waqar and Wasim formed a potent Pakistani partnership as did Marshall and Garner for West Indies. The recently-retired Lee is where you might expect him, about half-way down this list, just outside the indices of the really great bowlers. The index of Kallis is significantly below those of others in this table, just emphasising that there are limits to what even great all-rounders like the South African can do. An index of around 0.4 seems to separate the really great bowlers from those who were perceptibly less so.

The following table gives the same results for those Test bowlers with between 100 and 249 Test wickets (min V = 0.4):

 Player Wickets SR % tbb V George Lohmann 112 34.20 27.00 0.789 Sydney Barnes 189 41.66 30.81 0.740 Charlie Turner 101 51.28 33.72 0.658 Charlie Blythe 100 45.46 27.25 0.599 Saeed Ajmal 122 61.32 31.98 0.522 Bobby Peel 101 51.64 26.14 0.506 Mohammad Asif 106 48.77 23.28 0.477 Colin Croft 125 49.32 23.23 0.471 Clarrie Grimmett 216 67.19 30.84 0.459 Hugh Trumble 141 57.44 25.65 0.447 Saqlain Musthaq 208 67.64 30.09 0.445 Stuart MacGill 208 54.02 23.98 0.444 Fazal Mahmood 139 70.75 30.66 0.433 Bill O'Reilly 144 69.61 30.07 0.432 Graeme Swann 188 57.73 24.47 0.424 Darren Gough 229 51.62 21.63 0.419 Michael Holding 249 50.92 21.30 0.418 Terry Alderman 170 59.89 24.79 0.414 Shoaib Akhtar 178 45.75 18.66 0.408 Andy Roberts 202 55.12 22.40 0.406 Alec Bedser 236 67.45 27.40 0.406 Andy Caddick 234 57.94 23.27 0.402 Ian Bishop 161 42.25 20.92 0.400

Lohmann and Turner bowled in conditions that are rarely replicated today, small innings totals allowing them to bowl a greater proportion of overs, and with a more potent strike rate. Barnes is confirmed as the genius he truly was, while the index for Saeed Ajmal is interesting, and may in time, if continued, allow him to be classified as an all-time great.

The bottom five in this list are also of interest:

 Player Wickets SR % tbb V Trevor Bailey 132 73.58 14.72 0.200 Garry Sobers 235 91.91 17.84 0.194 Ravi Shastri 151 104.31 18.60 0.178 Ray Illingworth 122 97.82 16.82 0.172 Carl Hooper 114 120.95 13.22 0.109

At the risk of destroying the reputation of an icon, the placing of Sobers at this end of the table really does suggest that history may be overrating his contribution as a bowler. The jury is still out on whether he or Kallis has been Test cricket's greatest allrounder - but that is a topic for another day.

The complete list of the statistical measure V for all bowlers can be downloaded here