Evaluate a Stratego Battle
Haskell, 131 bytes

This solution is in the form of an infix function # with type String -&gt; String -&gt; String

Input is accepted through the two string arguments. The format for spotter input is 1 x where x is the guess.Output is given as a string. In the case where both units survive, the returned string contains both separated by a space.

My original solution was unfortunately bugged and the fix cost me a few bytes. 

('1':' ':x)#y|x==y="1"|1&gt;0="1 "++y
"S"#"10"="S"
"3"#"B"="3"
_#"B"="B"
x#y|x==y=[]
t@"10"#_=t
_#t@"10"=t
"S"#x=x
x#"S"=x
x#y=max x y