England are shorter than they were (1.58) before the off and although we expect them to win, any sort of resistance in the second innings from Pakistan could see the price drift. Indeed, as we move towards a fourth-innings chase we would hope that there could even be some flip-flops.
That is, of course, dependent on Pakistan showing resilience with the bat. These will be the toughest conditions they have faced so far on tour. The skies are overcast and there is plenty off the pitch and through the air. James Anderson, Chris Woakes (on his home ground), Stuart Broad and Steve Finn are a potent line-up.
The portents are not good. Pakistan were rolled for 72 in 2010 with Anderson (four wickets), Broad (four) and Finn (two) a three-man wrecking crew. Granted only Azhar Ali, of the batsmen, survives but it is personality rather than personnel which is key. The character of the batsmen in this Pakistan team is similar, not to mention the culture.
As we have said many times before players from the sub-continent are not used to seaming and swinging wickets. They are alien. So it is a mighty steep learning curve, even for the likes of Misbah-ul-Haq, who rather surprisingly is on his first tour of England.
Pakistan made a better fist of batting in the second innings in that match. They notched 296 thanks to some unexpected grit from Zulqarnain Haider, the wicketkeeper. A repeat of that should put the game finely in the balance.
Historically, tourists who have bowled first have scored well in the second match innings. Totals of 314-308-336-576-397-343 suggest a ding-dong affair awaits.
Those are numbers we shouldn't get too excited about, however. The timeline is a ten-year one from 2008 to 1998. Likewise the toss bias. In the last six Tests that have produced results five have been won by the team bowling first. Four of them by England.
We will be looking to get with England at prices from 1.70 and up because of the difficulty Pakistan should face having to make a score batting last. They might be able to hold off England's bowlers once, but twice is surely an Everest in these conditions.
It is underestimated how hard it is to bat fourth in Tests. The psychological pressure is often intolerable for batsmen, who play injudicious shots in the fear that, sooner or later, they will get one with their name on.
It is underestimated by cricketers themselves, oddly. Time after time we see captains bat on too long in the third innings so they set an improbable target instead of focusing on the number of overs they need.
Cook, in this regard, can a threat to a bet on England as we have discussed here. He has cost England victory before and will do so again. In favour of a wager on England here, though, is the fact that the hosts are level in the series.
At Old Trafford when he failed to enforce the follow-on Cook feared defeat - and almost certain series defeat - that he took overs out of the match instead of getting on with the job.
The worry of a chase in the fourth innings preyed on his mind on that occasion. That fragility is caused by the pitch, a worn, crumbling surface which has often had upwards of 200 overs. Uneven bounce, footholds and the two-paced nature of such wickets make batting hard.
Pakistan, although they would never admit it, would fear a chase of anything of 250 or more. So their second innings is pivotal.
If they achieve parity then we have the potential of a fourth-innings thriller with favouritism swinging this way and that. If they don't, a 50-run lead for England should ensure victory. That is five runs fewer than that first-innings average. It wouldn't be a surprise if they won by a 50-60 runs gap, too.
Fourth-innings chases at Edgbaston
124-2 Eng v Australia 2015
118-1 Eng v Pakistan 2010
283-5 SA v Eng 2008
81-4 Eng v SL 2006
279 Aus v Eng 2005 (target 282)
222 WI v Eng 2004 (target 479)
211-3 Eng v NZ 1999
Pakistan fourth innings averages
Asad Shafiq 48