Ballance sends powerful message
Middlesex 123 and 230 for 1 (Rogers 122*, Robson 77) need a further 242 to beat Yorkshire 178 and 416 (Ballance 130, Root 63, Lyth 54, Finn 4-89)
As each round of Championship games progresses, so another piece slots in to the jigsaw for Peter Moores and co. An England Test line-up that looked as uncertain as at any time in history a few weeks ago is gradually staring to come together. Arguably only injury will change the first-choice XI at this stage.
While Ballance's likely inclusion at No. 5 is not ideal - it may well force Ian Bell or, more realistically, Joe Root to bat at No. 3 - it is becoming almost impossible to suppress his inevitable rise. If Ben Stokes, Stuart Broad and Matt Prior are fit and Moeen Ali, perhaps batting as low as No. 8, is picked as the spinner (he has taken 88 first-class wickets at 31.10 apiece since the start of 2012), England have their side.
It is a shame to dwell on such matters when this game between Middlesex and Yorkshire, a fine encounter that has fluctuated in fortune each day, deserves attention in its own right. It has been an excellent advert for the quality and entertainment offered by county cricket. But if the county game exists to serve the England team - and that is certainly a key function - then it is probably wise to keep an eye on the bigger picture.
There may also not be quite as many opportunities to compete for a Test place as had been thought, either. It is likely that several of the participants in this match could be withdrawn from the next round of Championship matches to prepare for international duty.
The England squad for the ODI against Scotland is currently scheduled to be announced on Thursday and will meet for white-ball training sessions at Loughborough next Tuesday and Wednesday. While that would allow squad members to play the first two days of the next round of games - they could be substituted under the Championship competition regulations at the halfway stage - it does mean that their opportunities to impress the selectors in the red-ball game will be limited. The international season is, these days, almost endless.
It seems all but certain that Ballance's days as a county player are numbered. While no young player comes with guarantees, Ballance has the record, the hunger, the technique and the temperament to suggest that he will play at the highest level with distinction.
While a first-class average of 54.42 might be mitigated, partially anyway, by some success at a modest standard in Zimbabwe, it is harder to explain away the fact that he is the only man playing Division One cricket to have scored more than 1,500 Championship runs since the start of 2013 or that he has 406 runs already this season. He has scored four centuries in his last seven Championship matches.
Equally, there is the evidence of his strokeplay. While the final part of this innings came against modest bowling - Neil Dexter and Ollie Rayner were thrashed for the majority of the tenth-wicket stand of 66 in five-and-a-half overs - the power and range of stroke exhibited by Ballance was reminiscent of Kevin Pietersen at a similar stage of his career.
Ballance thumped 56 off 21 balls during that partnership, including five sixes and four fours, with one Rayner delivery slog-swept over the grandstand and out of Lord's and one fairly respectable Dexter delivery picked up and deposited over square leg in a manner that would have pleased Viv Richards.
Besides, Ballance had earned the right to such luxuries. By demonstrating the restraint and technique required to survive Middlesex's fine trio of mainline seamers earlier in his innings, he had worn down the attack and played himself in. By the time he late cut to third man - becoming Tim Murtagh's 500th first-class wicket in the process - he had helped his team set an improbable 472 for victory.
Only once have Yorkshire conceded more to lose a first-class match, when a Peter Trego-inspired Somerset made 479 for 6 at Taunton in 2009. While Cambridge University once chased 507 to win here against MCC in 1896, the highest successful chase by Middlesex at Lord's is 366 for 5 against Sussex in 1926.
But an opening stand of 181 in 38.4 overs has given them a chance. Chris Rogers, positive from the start, rushed to a century at almost a run a ball, driving crisply and proving merciless off his legs, while Robson survived a nervous start to lend increasingly assured support. The Yorkshire attack, so impressive the previous day, allowed their desire to get the better of them just a little and erred in both line and length on a pitch that has slowed in pace and eased in character, but still offers bowlers encouragement.
Robson might have gone without scoring. Drawn into prodding outside off stump, he edged low to slip off Jack Brooks where the ball appeared to not quite reach Adam Lyth, before settling in to play an innings full of the cuts and back-foot drives that may well become familiar to spectators of Test cricket over the coming years. He is not, at this stage, the complete player, and was eventually drawn into pushing at one he could have left to end the partnership but, as England look to the future, it is proving hard to ignore him.
There is, at some stage, a legitimate debate to be had about the reason players developed in Australia and southern Africa, in particular, appear to mature more quickly than those brought up only in England - the lack of cricket in state schools is surely a huge issue - but in Ballance and Robson, England have two 24-year-olds from southern climes who could serve them for much of the next decade.
George Dobell is a senior correspondent at ESPNcricinfo