Essex 122 for 3 (Westley 52*) trail Yorkshire 208 (Harmer 5-76) by 86 runs

If any county had a right to come to Chelmsford this season with preconceptions about the frenzied cricket that was surely bound to ensue it was Yorkshire. They managed to collapse to 50 all out here last year, an experience so maddening for their coach, Andrew Gale, that he reflected this week that at one point he asked the coach driver if he could put his bag on the bus.

The Yorkshire coach was parked up with its doors open during the morning session, presumably just in case Gale decided to make a run for it, but he stayed put on the balcony to watch Yorkshire dash to 208 at more than four an over.

Don't scoff - that's the highest first-innings score in nine attempts at Chelmsford in a season where Simon Harmer and Jamie Porter have reigned supreme, although Essex's response to be 122 for 3 at the close made them marginally the happier of the two sides. All this came, incidentally, after Yorkshire's captain Steve Patterson won his 11th successive Championship toss (when tosses have been necessary), a sequence with odds of 2048-1.

Last season's match produced a staggering turnaround. Yorkshire restricted their first-innings deficit to 92, Jonny Bairstow was promoted to open the batting in gung-ho fashion, Harry Brook followed up with a maiden Championship hundred (still his only hundred) on the second day and Yorkshire wrapped up the game on the third morning.

Yorkshire's preconceptions that this match will follow a similar course were justifiable enough because a dry pitch seamed and turned all day, but Alastair Cook has helped fashion two of Essex's four victories here - against Kent and Somerset - by providing method alongside the madness, so it is not the only way to go.

Harmer has exposed the fallibility of county batsmen against top-level spin all season and he duly returned 5 for 76 in 18.3 overs - his sixth five-for of the season, his Championship tally now swollen to 54 wickets at 17.05 - but Brook played him as enterprisingly as anyone, showing decisive footwork in making 46 from 60 balls on the ground where he made his greatest impact.

Brook, a former England Under-19 captain, was playing here in place of Jack Leaning, who made a pair earlier in the week at Scarborough. Brook began the season as an opener, where he played most of his age-group cricket, but he has a decent range of strokes and has a look of the middle order about him. As about 98% of batsmen in the country fit that description perhaps that should be no surprise.

Not that coming it at No. 5 exactly saw the shine off the ball. He took guard with Yorkshire 43 for 3 in the ninth over. Porter had two, Adam Lyth driving a wide, overpitched ball to cover and Will Fraine caught at the wicket after a quickfire 29. Gary Ballance had been cunningly silenced by Peter Siddle, who bowled him behind his legs, leg stump, as he shuffled back and across the crease.

Tom Kohler-Cadmore then succumbed to a big-turning long hop to give Harmer his first wicket, but Yorkshire countered with an enterprising stand of 59 in 12 by Brook and Jonny Tattersall. Harmer was briefly repulsed, but he bowled Brook on the outside edge to instigate lunch and struck again with his first ball after the resumption when Tattersall cut to the wicketkeeper.

Harmer ended the next salvage operation, too - 49 for the seventh wicket between Matt Fisher, who was playing because David Willey pulled out for personal reasons, and Keshav Maharaj. Both survived chances, but two lbw decisions silenced them, with Maharaj so befuddled in the flight that he attempted a stand-up sweep to a yorker. His task as the match progresses will be to match his fellow South African, Harmer. It will not be easy.

Harmer is now only three wickets short of his 57 victims last summer and with five matches remaining after this one needs only 21 wickets to surpass his tally when Essex won the Championship in 2017.

Tom Westley's second Championship fifty of the season stabilised Essex, but Yorkshire will be happy to have seen the back of Cook, caught at the wicket off Patterson. Patterson might never be ennobled in the Queen's New Year Honours, but he knows how to bowl on a pitch like this. The odds on the wicket then? Considerably less than 2048-1.