The importance of spin in middle overs of ODIs

After the demoralising defeat in the Test series, Australia were expected to be the frontrunners in the ODIs: South Africa were without their inspirational captain, and the replacement had only played 40 one-day internationals since his debut more than four years ago.

As it's turned out, though, Ricky Ponting and his team didn't solve the South African puzzle in the shorter version either, putting in such an insipid display in the fourth game in Adelaide that the captain called it their "worst performance of the summer by a long way".

And while it was a cakewalk in the end for South Africa in that game - they cruised home with eight wickets and almost 12 overs to spare - it didn't seem like they'd have such an easy day when Australia racked up a score of 93 for 2 after the first 15 overs of their innings. In fact, in most games of the series so far, Australia have been given more-than-useful starts - thanks primarily to Shaun Marsh - but they've then proceeded to botch it up in the middle overs.

Check out the table below and it's obvious that there's been little to choose between the two teams at the 15-over mark in all four games so far: Australia were in front in the first two, while South Africa were marginally ahead in the next two. The visitors' fightback in the middle overs has been a feature of every game, though, and that's been the passage of play where games have been won and lost.

The performance of bowlers in the middle overs, then, has been the key to this series. While Johan Botha, South Africa's captain, has been at the forefront of his team's effort between overs 15 and 40, Australia have had no weapon to call upon during this period: they've taken just eight wickets during these 25 overs, each costing them an average of almost 60 at nearly five runs per over. South Africa, on the other hand, have struggled to take early wickets, with just four in the first 15 at an average of 80.75, but they've hit back with 15 in the middle overs at a cost of just 30.40 each, which is about half as many runs as Australia conceded. It's still very early days in the year, but in matches played in 2009 so far, Australia have easily been the least effective bowling team in the middle overs. South Africa have done much better than them in the last 10 overs too.

Bowling performances of teams in first 15, next 25, and last 10 overs in ODIs in 2009

Team	First 15 - RPW	RPO	Next 25 - RPW	RPO	Last 10 - RPW	RPO
Australia	46.42	5.41	59.87	4.87	29.28	7.88
Bangladesh	14.23	3.32	17.04	2.85	24.44	5.86
New Zealand	35.00	4.41	34.44	4.93	11.00	7.54
Pakistan	50.40	5.60	47.25	5.04	18.80	7.42
South Africa	80.75	5.38	30.40	4.56	12.88	6.21
Sri Lanka	20.95	3.99	21.15	4.40	23.40	4.94
West Indies	36.22	5.43	38.77	5.49	46.50	9.30
Zimbabwe	22.57	3.51	24.66	3.63	14.90	4.17

Only includes teams that have played more than two ODIs this year.

These three defeats mean that just one month into year, Australia are already closing on the number of games they lost in all of 2008 - four. As the table below shows, Australia's bowling display in the middle overs was much stronger last year: in 18 games they took 81 wickets between overs 15 and 40, an average of 4.5 wickets per game. The cost per wicket was the lowest of all teams. South Africa and New Zealand did well too, with 64 wickets in 15 matches, while Sri Lanka had 104 from 26.

The three teams mentioned above have had spinners taking on a major workload in the middle overs. Ajantha Mendis and Muttiah Muralitharan have obviously done that job for Sri Lanka, while Daniel Vettori for New Zealand and Botha for the South Africans have also turned it on. In fact, 2009 has so far been an excellent year for spinners in the middle overs - they've taken 20 wickets more than the seamers, at a comparable average and a better economy-rate. A factor, obviously, is the number of games played in the subcontinent this year. In 2008, spinners conceded more runs per wicket, but their economy-rate was slightly better.

And finally, a table that shows the importance of spin in controlling the middle overs. Among the top 12 wicket-takers during this period of an ODI in the last year, 10 are slow bowlers. The top six has been completely monopolised by spinners, with Sri Lanka's two wizards leading the chart. Botha is an impressive fourth, with 19 wickets in 17 innings at an economy-rate of less than four runs per over. Pakistan's Iftikhar Anjum slots in the highest among fast bowlers, at No.7, while Mitchell Johnson is Australia's only representative in this list with 13 wickets in 17 games.

Australia have tried four slow bowlers - Nathan Hauritz, David Hussey, Michael Clarke and Cameron White - but none has matched his South African counterparts. The search for Shane Warne's replacement continues …