The last two weeks have been outstanding ones for James Anderson. At Headingley, in conditions which were just perfect for swing and seam bowling, he destroyed Sri Lanka's feeble batting with match figures of 10 for 45; in Chester-le-Street, the conditions were as favourable, but Anderson did his thing regardless, taking 8 for 94 and the Man-of-the-Match award.
In just 64.4 overs in this home series against Sri Lanka, Anderson has taken two-and-a-half times the number of wickets he took in 118.2 overs in South Africa earlier this year. The haul of seven wickets there cost him 43 runs per wicket; here, each wicket has cost him a ridiculously low 7.72 runs. The last time a bowler took 18 or more wickets in the first two Tests of a series in England was in 2000, by Courtney Walsh, who took 18 for 175; the previous such instance was by Terry Alderman in 1989 (19 for 339). These are special performances by a special bowler, who has proved repeatedly that there is no stopping him in home conditions.
Anderson's tally of 451 Test wickets is sixth in the all-time list and third among fast bowlers, next only to Glenn McGrath and Courtney Walsh. Sixty-five percent of those wickets have come in the six years of his 13-year international career, a period when he has clearly been at his most prolific. In his first 49 Tests, he averaged just 3.4 wickets per Test, and conceded nearly 35 runs per wicket. Those numbers have improved considerably in the last six years: the average has dropped by almost ten runs to 24.90, while the wickets per Test has improved to 4.28. There is also significant improvement in the economy rate - from 3.45 to 2.73 - which illustrates his superior control and his ability to constantly keep the batsmen under pressure.
Over the first part of his career Anderson was recognised, with some justification, as a bowler who was hugely reliant on the pitch and overhead conditions to take his wickets: in his first 49 Tests he averaged 43.84 in away Tests. In the last six years that away average has dropped to 28.06, while the average at home has also improved from 30.29 to 22.87.
Clearly, there is still some room for improvement in those away numbers. While he was outstanding in the 2010-11 Ashes series in Australia, taking 24 wickets at 26.04, in 2013-14, he only managed 14 wickets at 43.92. Add that to his numbers in the three-Test series in South Africa - seven wickets at 43 - and New Zealand (ten wickets at 37), and there is some justification in believing that Anderson is still a much greater force at home.
The big difference, though, is his numbers in Asia. Before May 2010, he had played five Tests in Asia and averaged 45.41; since then, in 12 Tests in the continent, his average has dropped to 23.51. Again, the economy rate of 2.43 in Asia in these 12 Tests speaks of an ability to keep it tight even when conditions are not favourable for swing, and the skill to relentlessly keep the batsmen under pressure has helped him and the other England bowlers pick up wickets.
Bowling with the new ball, often in favourable conditions, gives Anderson plenty of opportunity to attack top-order batsmen, and he has made the most of it, with almost 59% of his wickets being batsmen in the top five. Among bowlers in the 350-wicket club - there are 21 of them - only Sri Lanka's Chaminda Vaas has a higher percentage of top-five victims. His percentage is an incredibly high 62.53, which speaks volumes for his skill and also the fact that he was often the team's only high-quality seam and swing bowler.
McGrath is marginally behind Anderson, while the top ten is a virtual who's who of modern-day fast bowling. Dale Steyn, unarguably the greatest fast bowler of this era, is at No. 11 on this list with a percentage of 52.71. If the top six batsmen are considered instead of five, Anderson is in fourth place with a percentage of 65.85, behind Vaas, McGrath and Makhaya Ntini. (For a bowler who takes so many top-order wickets, it's a bit ironical that the batsman he has dismissed most often in Tests is Peter Siddle.)
Another stat that indicates an all-round improvement in skills is his average against left-handers. Before May 2010, Anderson did poorly against them, conceding more than 40 runs per wicket, while his average against right-handers was 31.73. Over the last six years, though, his average against them has improved to 22.91, which is slightly better than his average against right-handers. During this period he has dismissed David Warner seven times (average 24.42) and Kumar Sangakkara six times (average 16.33). In the period before May 2010, Sangakkara averaged 99 against Anderson.
In these last six years, Anderson is the leading wicket-taker in Tests. While it is true that he has played more Tests than other bowlers, there can also be no argument against the kind of numbers he has stacked up during this period. With Pakistan visiting for four Tests later this summer, expect him to add significantly to his already burgeoning wickets tally through the rest of this home season.