With England the clear favourites, the other three teams in Group B will all feel they have a good chance of securing the second qualification spot and perhaps this group could even have one of the best third place finishers.
Wales will be playing their first match at a major tournament since the 1958 World Cup and so they will undoubtedly be nervous as they will want to make sure they capitalise on this rare opportunity. Of course Gareth Bale is instrumental in their team and the Welsh will rely heavily on him to pull the rabbit out of the hat. However, they have a strong spine in the team with the likes of Aaron Ramsey and Ashley Williams and also have many other good Premier League players in all areas of the pitch. Their strong defence, led by captain Ashley Williams, should not be overlooked as they only conceded four goals in qualifying.
Slovakia have not been at a major tournament since the 2010 World Cup but are one of those teams who could spring a surprise at any competition, as they did in 2010 when they beat Italy to knocked them out to qualify from the group themselves. The squad has a good mix of both youth and experience which could serve them well. Marek Hamsik is undoubtedly their Bale-style talisman.
The bookies have made the Slovaks slight favourites for this match, perhaps only for their superior tournament experience in comparison to Wales and their recent victory against Germany in a friendly. Having said that, I think Wales will be incredibly fired up for this match and I would therefore expect them to come out on top. I think Wales to win at 15/8 is incredibly kind.