7 V 10 in war?

[Guvnor]

It doesn’t happen often but it does happen. One of the better explanations of war matchmaking:

@jinbatsu

War Match Order from Top to Bottom Factor Priority

• The best 30 heroes in hero roster of each Alliance member opted in for war
• Out of the 30 heroes, the most weight is put on the best five heroes of each Alliance member
• Player count of the Alliance (also subtracting those who have opted out) - they try to get an even number of players on both sides, but it can vary by up to three members.
• The troop strength of the best in each element
• War history (minor impact compared to Hero Power)

Note things like war scores fluctuate before & after matchmaking based on players who are / not opted into wars so what is visible when CHECKED may not be the same as when MATCHED.

Another handy graphic:

@Rook

Some folks start here:

Remember that ALL of these are in play during war matchmaking: It is possible—through a series of wins—that you have stepped up toward a much higher opponent. And they—through a series of losses—might have stepped down toward you. That’s just taking into account the “Win/Loss” factor.

And some other miscellaneous links:

• Alliance Wars Matchmaking (Discussion & Developer Response) MASTER
• War matchmaking strikes again
• "New" alliances in war must be resolved
• Shuffle war strategy
• Help me understand (war related/ war shuffle strategy)