James Anderson nails another right-hand victim, but against left-handers the wickets haven't come as easily © Getty Images

After tormenting New Zealand in the three-match away series in March, Ryan Sidebottom and James Anderson were again the chief wreckers in a series Daniel Vettori and his team will want to quickly forget. Sidebottom had taken the lead role in New Zealand, but this time the load was shared more equally: Anderson's haul of 19 wickets was his highest in a single series, and pipped Sidebottom's series tally by two. Even if those wickets weren't against top-class opposition, the two gave enough glimpses to suggest that South Africa's batsmen could be severely tested if both bowlers maintain their groove later this summer.

Sidebottom's display was hardly surprising, but Anderson showed yet again what a force he can be when he is on song. Since taking that five-for in a high-class performance against India at Lord's last year, he has been in remarkable form, taking nearly half his 89 Test wickets in the last 11 months. During this period his wickets have cost him 30.58 each, and have come at the superb rate of one every eight overs - among bowlers who have taken 20 wickets during this period, only three have a better strike-rate. In comparison, the stats from his first 16 Tests are very ordinary - he averaged fewer than three wickets per Test and gave away more than 38 runs per dismissal.

Anderson's Test career in two parts
Period Tests Wickets Average Strike rate 5WI/ 10WM
Before July 2007 16 46 38.39 60.4 2/ 0
Since July 2007 9 43 30.58 48.4 3/ 0
Total 25 89 34.61 54.6 5/ 0

If conditions continue to aid swing bowling, there is every reason to believe he will be a force against South Africa as well, but there is one area in his bowling which he, and with the team management, needs to address urgently: his performance against left-hand batsmen. His natural outswingers have troubled plenty of right-handers, but that swing hasn't had much effect on the lefties, who've found it easy to play him off their pads for runs.

In the two series against New Zealand, Anderson has struck 27 times at a superb average of 24, but 22 of those dismissals have been right-handers. Against the lefties he has been rather ordinary, and the only one he dismissed more than once during this period was Daniel Flynn. In the 228 deliveries he bowled at Stephen Fleming, Jacob Oram and Daniel Vettori, he only got them out once each. In contrast he nailed Aaron Redmond and Jamie How, the New Zealand right-hand openers, four times each in a combined total of 200 balls, while Brendon McCullum fell thrice to him in 71 deliveries.

Anderson v New Zealand
Versus Wickets Average Strike rate Econ rate
Right handers 22 20.77 31.64 3.93
Left handers 5 38.60 55.80 4.15
Total 27 24.07 36.10 4.00

Sidebottom, on the other hand, has been on target against both kinds of batsmen, though his numbers against left-handers is truly incredible - in his last two series against New Zealand, he has dismissed them 16 times, conceding fewer than 15 runs per wicket. Oram and Vettori have handled Anderson comfortably, but they've been clueless against Sidebottom, falling to him six times each in a combined total of 342 deliveries. Fleming has fared no better, perishing three times against Sidebottom in 112 balls.

Sidebottom v New Zealand
Versus Wickets Average Strike rate Econ rate
Right handers 25 21.08 44.40 2.84
Left handers 16 14.43 32.25 2.68
Total 41 18.48 39.60 2.79

Together, though, Sidebottom and Anderson have been perfect for England. While one has dominated left-handers, the other has had the right-hand batsmen clueless. Combine their stats over the last four months and it turns out that batsmen of both types have struggled equally to combat the menace of these two.

Anderson and Sidebottom v New Zealand
Versus Wickets Average Strike rate Econ rate
Right handers 47 20.93 38.43 3.26
Left handers 21 20.19 37.86 3.20
Total 68 20.70 38.25 3.24

Sidebottom's presence lends balance to the table above, but it doesn't hide Anderson's lack of success against the left-handers. His career stats against them are dismal - of his 89 Test wickets, only 19 have been lefties, and each of those has cost him nearly 55 each, while the strike-rate diminishes to a wicket every 13 overs, which is five overs more than it takes him to dismiss a right-hand batsman.

Anderson v right- and left-handers in Tests
Versus Wickets Average Strike rate Econ rate
Right handers 70 29.11 48.34 3.61
Left handers 19 54.94 78.00 4.22
Total 89 34.61 54.60 3.79

Sidebottom's career numbers are far more evenly distributed - he obviously doesn't mind much who he is bowling to.

Sidebottom v right- and left-handers in Tests
Versus Wickets Average Strike rate Econ rate
Right handers 44 26.43 56.59 2.80
Left handers 26 22.88 49.15 2.79
Total 70 25.11 53.80 2.79

More than one left-hand batsman has had the measure of Anderson, but the one who has scored the most runs against him is also the one who will be leading the South Africans in England over the next month. Graeme Smith has so far completely dominated Anderson, scoring 165 runs off him at more than five an over. Among the others in the top ten are the three New Zealanders mentioned earlier. Not only has Anderson struggled to take their wickets, he has also leaked runs at an alarming rate.

Left-hand batsmen who have dominated Anderson
Batsman Balls/ runs Dismissals Average Runs per over
Graeme Smith 188/ 165 1 165.00 5.26
Gary Kirsten 167/ 111 0 - 3.98
Kumar Sangakkara 129/ 99 1 99.00 4.60
Michael Hussey 123/ 69 1 69.00 3.36
Stephen Fleming 85/ 66 1 66.00 4.65
Daniel Vettori 58/ 59 1 59.00 6.10
Justin Langer 77/ 50 1 50.00 3.89
Jacob Oram 85/ 49 1 49.00 3.45
Matthew Hayden 62/ 40 0 - 3.87
Sanath Jayasuriya 51/ 38 0 - 4.47

The right-handers listed below, though, have clearly come out second-best in their battles against Anderson. Sachin Tendulkar had a torrid time against him last summer, while Wasim Jaffer and Rahul Dravid didn't fare much better. Anderson has also kept the immense Jacques Kallis under control, dismissing him twice in 119 deliveries and keeping him to less than three runs per over.

Right-hand batsmen who have struggled against Anderson
Batsman Balls/ runs Dismissals Average Runs per over
Jamie How 140/ 86 4 21.50 3.68
Sachin Tendulkar 160/ 78 4 19.50 2.92
Brendon McCullum 71/ 74 3 24.67 6.25
Wasim Jaffer 150/ 67 3 22.33 2.68
Jacques Kallis 119/ 58 2 29.00 2.92
Rahul Dravid 130/ 52 3 17.33 2.40

S Rajesh is stats editor of Cricinfo