England have had to digest back-to-back defeats by margins of six wickets and 69 runs against Sri Lanka - but they have an alternative method of assessing their Series woes.

There could have been little doubt in anyone's mind, at Headingley and Lord's last Friday and Sunday, that the hosts had been significantly outplayed.

But England have an extra means of pinpointing where they have gone wrong, and slid 2-1 down in the Series going into today's fourth match of five at Trent Bridge - courtesy of bowling coach David Saker's 'Matchswing'.

Since Saker's arrival, just before their victorious ICC World Twenty20 campaign last year, England have been invited at each post-match debrief to check how they rate on his patent scoresheet.

'Matchswing' - kept under wraps, until Graeme Swann chose to go public yesterday - penalises bowlers and fielders for unforced errors.

"We've got a scoring system called our 'Matchswing', and it's been off the charts in the last two games," said Swann.

His revelation conjures mental images of televisual aids such as the BBC's election 'Swingometer'.

Having thrown 'Matchswing' into the public domain, though, the off-spinner is intriguingly cagey on details.

"It's a system we've got, a way of marking how you're performing," Swann continued.

"It's a team thing - our own little way of marking our own performances. I can't go into it. It's not been good.

"It is not a particularly complicated system - it can't be... because the bowlers have to work it out.

"It is a simple way of logging your performance. It is for the whole team but it's driven by the bowlers."

'Matchswing' appears to operate on a collective points differential, offsetting mistakes against successes.

The scorebook from Lord's records ten English wides - a factor doubtless replicated in their 'Matchswing' total.

It is unclear whether the rating system requires pen and paper - or maybe more modern technology.

Either way, it has typically indicated a pleasing level of consistency - although not at this year's World Cup, where England lurched to extremes which culminated in a ten-wicket quarter-final defeat against Sri Lanka.

"Our one-day record has been very good, so our 'Matchswings' have been good," said Swann.

"Saker's belief is that you cannot win a match if you have a very bad 'Matchswing'.

"In the World Cup they veered wildly, because one day we were 'filthy' and the next we were world-beaters. It is all about getting back to being world-beaters every game."