Before you know it, theories about cricket have become accepted as fully-fledged fact. If they were drugs trials there could be all sorts of potential trouble with a wonder cure being written up in The Lancet and marketed long before completion. Thus, it has been deemed as gospel that the Sri Lankan bowling attack, deprived of its glory boys, is not up to it for the forthcoming Test series against England. That may prove to be so by the end of this tour, but they confounded the blanket scepticism in their opening game yesterday.
Middlesex, albeit well below strength, which is saying something, capitulated. They were 161 all out, losing their last nine wickets in little more than a session. Whatever the frailties of the batting, and they were many, it rather suggested that the conclusion about the lack of the tourists' threat was premature. On a pitch which had been blameless for the first two days – unless being too flat is cause for culpability – all five of their bowlers took wickets.
The most impressive were the two whom they would probably prefer to select for the first Test in Cardiff next week. Chanaka Welegedara took three wickets with some lively left-arm fast medium. He was hardly quick but he achieved some bounce and was plainly delighted to remove Andrew Strauss, England's captain. It was a typical Strauss dismissal, opening the face and cutting, come driving, off the back foot to gully.
There were three wickets too for Ajantha Mendis, a mystery spinner who has been detected somewhat since his early days. When Mendis burst on to the scene three years ago his carrom ball carried all before it. The imminent loss of Muttiah Muralitharan would not be so gravely felt after all.
Mendis has not trained on as he might have done. Batsmen tend to read him as though he was Janet and John rather than Sanskrit these days. He was omitted from Sri Lanka's side for the World Cup final and his brief sojourn with Somerset at the start of the season was hardly a resounding success.
His two Championship matches brought him four wickets but there was no fluency let alone threat. Those who saw him were surprised that he had been so garlanded recently. Mendis was hardly a handful yesterday but he was too adroit for Middlesex and the one with which he bowled Jamie Dalrymple suggested he has not become entirely straightforward. The challenges ahead for Mendis and Sri Lanka are more imposing than this.
The stand-in captain, Dawid Malan, was Middlesex's top scorer but like too many of his colleagues he was out, caught at slip, playing a ill-executed shot. The England under 19s star, Adam Rossington, just 18, avoided a pair by the narrowest streaky edge for four, but he found it a struggle. Rossington has plenty of admirers and enough about him to make a go of the game but in his first-class innings so far he has made 1, 0 and 4 so he has left scope for improvement.
Left with 213 to win, Sri Lanka might have done it at a doddle. They fiddled about with their batting order, worryingly aware that they have only one more match before the Test series starts, and that the relatively serious business of facing England Lions, players with points to make.
For a while, it looked as though Middlesex's attack might go through the game wicketless. Although the tourists had nominally been two down in their first innings they both emanated from the batsmen retiring out. When Prasanna Jayawardene advanced too far up the pitch the bowler Tom Parsons ran him out with a direct hit but still the bowlers had not struck.
Dalrymple and Tom Smith, however, made incisions with off spin and left-arm spin respectively, which curtailed Thilan Samaraweera's clear intentions to bat throughout the innings.
In the event, they lost six wickets in the pursuit including Tillakaratne Dilshan, the captain, and Tharanga Paranavitana, more conventionally dismissed this time, but there was never much doubt that the necessary runs would be easily accrued. By the end of the Lions match more will be known about these Sri Lankans but they will be no cakewalk.