Broad can't put his finger on inconsistencies

London - England seamer Stuart Broad admits he and his team are struggling to find answers as to why they are so inconsistent in Test cricket.

South Africa thumped England by 340 runs at Trent Bridge in the second Test of the four-match series that followed the hosts beating the Proteas by 211 runs in the first Test at Lord's.

The results follow a worrying trend for England in the longest format of the game since Australian Trevor Bayliss took over as coach in 2015. 

Under Bayliss, England have played 30 Test matches and only won two games in a row on three occasions. 

In a column for the Daily Mail, Broad wrote: "We know it's not the first time we've followed a good performance with a bad one. 

"We spoke about it with coach Trevor Bayliss, and what we need to do to change the trend. It's hard to put your finger on why it keeps happening. 

"It's not that we relax mentally after a win. In fact, maybe we try too hard and put too much pressure on ourselves." 

Broad though feels an experience in the 2015 Ashes series against Australia has given the home team belief ahead of third Test against the Proteas, which starts on Thursday at the Oval.

Two years ago, England and the Aussies won one game each before a week break between the second and the third Tests - the same as in the current series - saw England come back and win the next two games. 

The paceman continued: "What's happened so far against South Africa reminds me of the 2015 Ashes. We beat Australia easily in the first Test at Cardiff, then lost the second badly at Lord's. 

"After that, we had a bit of gap before the next game - as we have this time - then had two good wins at Edgbaston and Trent Bridge. We're planning to draw on that experience now."