Onions makes his well rehearsed case
Durham 308 and 152 for 7 (Trego 3-46) lead Somerset 185 (Trego 48, Rushworth 4-52, Onions 4-65) by 275 runs
This is a match report that could, to a large extent, have been written with the cut and paste keys.
As has so often been the case in recent times, this was a day's play characterised by fine bowling from Graham Onions and featuring a visiting batting line-up struggling to cope with the moving ball on a helpful pitch. It was classic Durham; classic Onions. Pretty much like a band playing their greatest hits.
Quite what else James Whitaker, the national selector, expected when he came to Durham is unclear. He knows that Onions - and the largely unsung Chris Rushworth - is a tough proposition in these conditions and he surely cannot have expected him to gain more pace, learn new tricks or even have deteriorated after several years of outstandingly consistent cricket. If England select Onions, they know exactly what they will get.
That was a point made by Onions after play. Perhaps frustrated by the question - it is hardly the first time he has spoken on this subject - or the circumstances, he made little attempt to sugar-coat his feelings.
"He knows exactly what I'm about," Onions said. "He saw me in Sri Lanka, as well, when I was there with the Lions.
"As a cricketer there is nothing more I can do. I am doing all I can to produce results and to play for England. But the bottom line is that I've done that for the last four or five years. I've just got to keep knocking on the door."
The problem with games at Chester-le-Street, however, is that they do not replicate conditions found in international cricket. While it is true that not many county grounds in April will replicate the sort of surfaces found at Test level, in Durham that is taken to an extreme. So only one batting bonus point was conceded at home by Durham in the 2013 season and not once has an opposition team scored 300 in their first innings here in the last two years.
So while Rushworth and Onions, maintaining tight lines and generating movement, troubled batsmen throughout and made a strong batting line-up appear fragile, it is of limited use for Whitaker has he seeks to apply such skills to the demands of international cricket.
Yet many of the virtues of bowling remain the same whatever the surface. So Onions' consistency, his stamina and his ability to extract movement both in the air and off the seam when conditions allow, would always render him a reliable performer for England. But he could play Test cricket for a decade and never find a surface like this. He could play Test cricket for a decade and never find a surface that offers such variable bounce in the first innings and he could play for a decade and not see the ball nip around to this extent.
Equally Keaton Jennings, Durham's impressive opening batsman, has acquired a technique that seems ideally suited to these surfaces. Using his height, he prods half forward, is remarkably disciplined about not playing away from his body, and waits for the ball in one of his three or four scoring areas. It is the basis of a decent game and, in temperament at least, he has a great deal going for him. But sterner tests await on tracks that turn or against fast bowlers that will challenge that forward prod.
All that leaves Whitaker with a difficult choice to make. Onions' case remains compelling but, with the younger men like Chris Jordan forcing their way into the reckoning, England may be reluctant to select a seamer who will be 32 before the end of the season. Unless Onions is able to unseat James Anderson or Stuart Broad - and that it is not completely impossible, as both will need rest - it is hard to see him winning a recall in anything other than a crisis.
That Somerset ended the day still in with a chance of victory - Yorkshire chased down a target of 339 here in April last year - was largely due to some sloppy batting in Durham's second innings. While both Lewis Gregory and Peter Trego, who also produced a typically brave counter-attacking contribution with the bat, deserve credit for delivery the best part of 40 overs each over the first two days of the game, they enjoyed little support.
Somerset donated another 10 runs in no-balls - that is 40 in the match so far - and several Durham wickets fell as the result more of careless batting than fine bowling. Michael Richardson, for example, pulled a long-hop to mid-wicket, Scott Borthwick was brilliantly caught as he turned a half-volley off his legs and Jennings drove uncharacteristically loosely at one that turned out of a foot-hole.
Onions appeared unimpressed by his colleague's batting. "If we're honest, the application we showed with the bat could have been better," he said. "The batters will be disappointed, I'm sure. We could have put them out of the game. But if we bowl well, as we did today, I'm sure we'll win."
Somerset's situation is not helped by something of an injury crisis. With three first choice seamers - Steve Kirby, Alfonso Thomas and Craig Overton - unable to take part in this game due to injury, they could have done without Craig Meschede sustaining a side strain and Nick Compton suffering a neck spasm that forced him to bat at No. 8 in Somerset's first innings. An injection appears to have brought little comfort and he was unable to take the field in the evening session. His involvement in the second innings, and in the next game, must be in doubt.
Compton was, therefore, unable to make much of an impression on Whitaker. He may have felt it was typical of his fortune that he was last man out, adjudged leg before to a ball he seemed to have hit really quite hard.
"We didn't bowl very well at all on day one," Dave Nosworthy, the Somerset director of cricket admitted. "And we didn't start well with the bat, either. But we showed a lot of courage and character later on and by no means is this game over."
Somerset will have to bat far better second time around, though. Marcus Trescothick does not look anything like the batsman he once was and, though the line-up is deep and contains several fine stroke makers, they are up against an expert in his own backyard. Durham's lead of 275 may well be enough already.
George Dobell is a senior correspondent at ESPNcricinfo