The Carlton Mid One-Day Tri-Series is only three matches old, but certain trends have already emerged. A prominent one has been the dominance of fast bowlers in the games so far: Mitchell Starc has ten wickets in two games - with a six-wicket haul and a four-for - Steven Finn took five against India, while James Anderson and Chris Woakes both have a four-for each. In contrast, no spinner has taken more than one wicket in a match so far. The total number of wickets taken by spinners so far is as many as Starc took in a single game, against India. Spinners have averaged 54.50 runs for each of their six wickets, while fast bowlers have taken 35 wickets at 27.57; spinners have taken a wicket every 65 deliveries, while fast bowlers have struck every 32 balls.

These numbers could change as the tournament goes along, and perhaps spinners will pick up more wickets in conditions that aren't as seamer-friendly as the Gabba was when England played India, but these early numbers only continue what has been a trend in ODIs in Australia. In the last six years (since 2009), spinners haven't done so badly in Australia in terms of economy rates - they've conceded 4.86 runs per over, compared to 5.21 by the fast bowlers there - but in terms of wicket-taking ability, they've struggled, conceding almost 45 runs per wicket compared to 30 by the fast bowlers. They've taken a wicket every 55 balls, compared with 35 by the faster men. The average is the poorest among all the countries which have hosted at least 50 matches during this period.

Going into the World Cup, this could be a key factor which teams will need to consider. The 2011 tournament was played mainly in India, where fast bowlers have performed the poorest among all countries since 2009 - both in terms of average and economy rate. From there, the tournament moves to countries where spin is unlikely to be a wicket-taking option - in New Zealand too, they average more than 42 runs per wicket.

Spinners in each country in ODIs since Jan 2009 Host Matches Wickets Average Econ rate 5WI Bangladesh 84 592 28.65 4.34 3 West Indies 66 302 32.22 4.48 2 England 74 286 32.76 4.88 3 UAE 65 337 32.83 4.46 4 Sri Lanka 86 413 34.38 4.80 4 India 84 446 37.14 5.03 2 Zimbabwe 56 307 38.29 4.70 3 New Zealand 53 148 42.37 4.92 0 South Africa 67 205 44.14 5.01 0 Australia 70 176 44.88 4.86 0

Fast bowlers in each country in ODIs since Jan 2009 Host Matches Wickets Average Econ rate 5WI West Indies 66 598 29.99 4.99 3 Sri Lanka 86 698 30.04 5.21 11 Australia 70 792 30.05 5.21 15 South Africa 67 685 30.56 5.19 7 UAE 65 532 31.32 5.03 6 Bangladesh 84 558 31.36 5.15 8 England 74 676 33.30 5.20 5 New Zealand 53 501 34.01 5.59 6 Zimbabwe 56 391 35.15 5.25 5 India 84 651 38.35 5.73 6

Teams from the subcontinent have often based their bowling strategy around spinners doing the bulk of the work in the middle overs. In the subcontinent, spinners tend to take a fair number of wickets in the middle overs, in the process stifling the runs and also ensuring that batting teams have fewer wickets in hand during the slog overs to take full advantage.

However, in Australia and New Zealand, spinners have especially struggled to take wickets in the middle overs: those are the only two countries where spinners average more than 50 runs per wicket (South Africa comes very close too), and also the only countries where spinners average less than one wicket per innings in the middle overs of ODIs. In India, spinners average around 1.75 wickets per innings in the middle overs. Given these numbers, teams will need to rethink their bowling strategies in the middle overs, with more emphasis on pace through most of the innings.

Spinners in the middle overs (15.1 to 40.0) in each country since Jan 2009 Host Inngs Wickets Average Econ rate Bangladesh 163 348 31.77 4.25 England 140 199 34.38 4.72 UAE 121 208 34.87 4.41 West Indies 123 180 35.26 4.35 Sri Lanka 161 257 40.39 4.65 India 165 289 41.50 4.89 Zimbabwe 95 141 47.31 4.57 South Africa 125 143 49.48 4.94 Australia 132 120 51.44 4.76 New Zealand 97 88 52.59 4.77

The 2011 World Cup was different from the others before it in terms of the number of overs spinners bowled with the new ball. In the first 15, almost 28% of the overs were bowled by spinners - 402.2, out of 1445.1. In the three previous World Cups, it had never exceeded 7%. Zimbabwe, Bangladesh and India used this strategy much more than any other team: Zimbabwe bowled 60 overs of spin in the first 15, Bangladesh 56.2, and India 52. With two new balls in use this time, and conditions likely to help pace and seam, the percentage of early overs bowled by spin will also surely drop significantly this time.

Overs bowled by spinners in the first 15 in each World Cup since 1999 Year Overs Wickets Average Econ rate Tot overs Percent 2011 402.2 47 34.00 3.97 1445.1 27.84 2007 86.2 7 66.14 5.36 1521.0 5.67 2003 105.0 16 34.56 5.26 1522.0 6.90 1999 45.0 11 20.18 4.93 1243.4 3.62

Over the last three World Cups, spinners have done pretty well, averaging less than 33 in each edition, and conceding less than 4.80 runs per over. In fact, spinners have been fairly economical in all World Cups - also partly because they tend to bowl during the easier overs in an innings - but in 2011 they also took more wickets than ever before, finishing with a tally of 290; the previous record for spin in a tournament had been 201, in the 2007 edition in the West Indies. The last time Australia-New Zealand hosted the tournament - in 1992 - spinners took 94 wickets at 35.29 and an economy rate of 4.16, compared to the fast bowlers' tally of 344 wickets at 31.58, and an economy rate of 4.23.

Spinners in each World Cup Year Matches Wickets Average Econ rate Str. rate 1975 15 27 43.70 3.62 72.2 1979 14 8 65.25 3.27 119.3 1983 27 47 36.44 3.61 60.5 1987 27 106 37.13 4.34 51.2 1992 39 94 35.29 4.16 50.8 1996 36 169 33.23 4.50 44.2 1999 42 87 40.71 4.67 52.2 2003 52 195 31.44 4.54 41.5 2007 51 201 32.20 4.79 40.2 2011 49 290 31.51 4.60 41.0

And finally, a look at some of the spinners in Australia and New Zealand over the last six years. Most of the top ones have struggled for wickets, though they've been pretty good at keeping the runs in check. Spinners of the caliber of Daniel Vettori, Rangana Herath and Sunil Narine have averaged more than 36 runs per wicket, while R Ashwin, Ravindra Jadeja and Nathan McCullum have averaged more than 60.

Most of the bowlers listed below are a part of their team's plans for the 2015 World Cup. If the pitches are drier - as they might be towards the end of the season - these bowlers might end up with better returns than the stats below suggest. Otherwise, their main role will be to hold an end up and ensure that they don't leak too many runs.