Nottinghamshire 408 and 329 for 5 dec (Clarke 97*, Nash 75, Duckett 61, Mullaney 52) lead Yorkshire 291 (Root 73, Patel 3-31) by 446 runs

Joe Root, struck on the helmet, first ball by Stuart Broad. It did not auger well for Yorkshire. It did not feel all that great for Root. But that was the lowest point of the day for England's Test captain as unbeaten hundreds of considerable resolve by Root and Gary Ballance enabled Yorkshire to secure a draw against Nottinghamshire at Trent Bridge without further alarm.

Nottinghamshire had declared overnight with a lead of 446 and accounted for Yorkshire's opening pair in the space of 11 overs, but light faded from their challenge as the day progressed and a draw was agreed at five past five with Yorkshire 277 for 2.

Most of the attention will rest with Root, who was making one of his rare Championship appearances for Yorkshire and who initially seemed intent on collecting enough injuries to complete a Box Set. An injured finger while fielding on the third evening was followed by a rattled helmet on the fourth morning as he ducked into a bouncer that failed to get up.

That entailed an eight-minute delay while Root awaited a helmet and was checked for concussion. Time also to reflect on the nature of a moribund but slightly uneven pitch and how to adjust his technique to combat it. He joked that he was unhappy that Broad did not follow up with a volley of abuse.

On one of those two-temperature sunny days in early Spring in which youngsters wear t-shirts and those of greater years still don winter coats and sweaters, Root and Ballance then batted out the rest of the day in a manner that justified the optimism of their coach, Andrew Gale, on the previous evening that a draw was well within their grasp.

The closest they came to being split in a stand of 253 in 67 overs was when Ballance misjudged a single into the off side but Jake Ball failed to follow up a good stop by throwing down the stumps. Root also survived a big appeal for 46 for a catch down the leg side as he hooked at Paul Coughlin.

A burst of three successive boundaries then took Root past 50, Nottinghamshire's slips disappeared with an air of resignation, and runs came with growing ease. Nottinghamshire's deep-set fields by the end even hinted that they half imagined Yorkshire might have a tilt at a ten-an-over run chase. Instead, a draw was agreed upon completion of Ballance's hundred.

On such a placid surface, Nottinghamshire resorted to a regular supply of short balls, something that Root felt was a good lesson for county bowlers so often reliant on seaming pitches. "It's nice now to see bowlers exploiting a different plan, and to go short. I'm sure we will see a lot more of that if the surfaces stay the same and it will be great for the development of the next generation, and the players who are just below the current England team.

"You want to set the example and try and use your experience to your advantage, but I think I did ride my luck on occasions. It's always hard to say it's one of your best knocks when you've not won the game. I took a few painkillers just so it didn't distract me from what was important but the head feels fine and the hand feels fine. The only thing that was hurting when Broady hit me was my ego."

Root carries a nation's hopes for the Ashes; Ballance, by contrast, although only 29, has fallen out of favour and appears to have played the last of his 23 Tests - against South Africa on this ground nearly two years ago. Yet in first-class cricket Root and Ballance reach fifty in a higher percentage of innings than any other current English-qualified batsman, better than one in three. And when it comes to the percentage of hundreds, Ballance is unsurpassed.

Steven Mullaney had declared Nottinghamshire's second innings overnight on 329 for 5, leaving Joe Clarke stranded on 97 not out, three runs short of becoming the youngest player to make two hundreds in a match for the county - and on his debut for the county, too. Team needs above all other considerations had been strictly applied and adherence to such a principle should not be lightly dismissed.

"It was my decision," Mullaney said, "but I spoke to Joe and he was the first one to come up to me last night when he wasn't out and he said whatever is best for the team and if you want to declare. That's the sort of bloke he is and the sort of team that we want to build."

Ball took both wickets to fall, having Harry Brook caught at third slip for 2 and Adam Lyth played on for 21. Root has one more Championship match for Yorkshire, at the Ageas Bowl; Ballance is around all season and ultimately it will be his form, as much as anyone's, which will determine Yorkshire's season.