Kick-off: 19:45 BST
Live On: ITV
Analysis of this market is muddied a little by speculation about the coaches' tactics.
Slaven Bilic might go on the attack against Group C's weakest nation, but he could stick with the more cautious approach that got his latest, less gifted Croatia team to the finals.
Giovanni Trapattoni might see this match as Ireland's best chance of three points, but he could be happy to bank a single point and hang on for a winner-takes-all clash in the third group game with Italy, against whom his Irish charges are unbeaten in three previous clashes. Stephen Hunt seems to favour the latter option.
Croatia have only beaten Ireland once in their last six meetings - it might take Opta to remind you that these two last met in a competitive fixture in a Euro 2000 qualifier - but start as 2.47/5 favourites. Ireland's record of finishing level with their opponents in five of their most recent nine games suggests the draw is better value at 3.211/5. This match is likely to be one of few goals - assuming it will not in fact be a clash of two teams in all-out-attack mode - and that too persuades us towards the draw.
Ten of Ireland's last 12 games under Trapattoni have finished with Under 2.5 Goals. The boys in green conceded only twice in their last seven qualifiers and are a good fit with the European Championships' pattern of tight opening games: 35/48 have stayed Under 2.5 Goals since the tournament matured into an eight-team affair in 1980. The imbalance is less marked in 16-team competitions like this one (20/32 Under 2.5 Goals since 1996) but it is still there.
Croatia play keep-ball, but lack penetration. That's a good way to keep goal counts down: as Barcelona and Spain have taught the world, possession is a great defensive tactic; and if you're unlikely to find a way through yourself, well...
Luka Modric, Croatia's chief creator, is tired (and perhaps a little emotional too) after the rigours of letting Spurs' Premier League campaign slip into Europa League-shaped oblivion. He's so tired he's on a special training programme, in fact, so it's not clear he will be operating at full fitness in time for his team's opening game and this too encourages thoughts of Under 2.5 Goals. The 1.564/7 on offer about that is hardly generous, however.
If you believe in the draw and also in Under 2.5 Goals, there are only two possible outcomes: 0-0 and 1-1. The goalless draw might have more appeal at slightly longer odds (7.613/2), especially in the light of Ivica Olic's absence, but splitting your stake across the two will return similar payouts if either of them turn out to be the correct score.
Ireland committed more fouls in qualifying than anyone else now in Poland or Ukraine. Even in this exalted company, one man stands head and shoulders above his team mates: lunge forward, Richard Dunne. The Aston Villa centre-half will lead from the back, throwing himself with manly abandon at ball and opponent alike. He saw yellow four times in ten qualifiers and anything beyond 2.56/4 would make him a value bet to get booked on Sunday.
On the other side, Dario Srna, a prancing wing-back in popular lore, might be overpriced to earn a caution. Croatia's captain is as good at conceding free kicks as he his at taking them. With lots of ground to cover on his team's right-hand side, he too was booked four times in ten qualifiers - and also in 3/5 Champions League games with Shakhtar Donetsk this season.
Croatia won more corners in qualifying than anyone else (86). Among the 14 qualifiers, only Denmark (38) notched fewer than Ireland (42). Trapattoni's team are likely to cede possession to Bilic's men and, with unwieldy full-backs like Ward and O'Shea, are unlikely to pose much of a wide threat when they do have the ball.
Best Bet: Back Croatia @ 1.758/11 in Corners Match Bet
Other Recommended Bet: Back Richard Dunne To Be Shown a Card @ 2.68/5
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