been playing a load of player matches recently, searching by same skill, but i either get some a ton better than me or someone that doesn’t know what they’re doing 
is it done by BP?
yes, i believe it is determined by bp
What about player matches? Are those also determined by BP? There has to be more to it than that.
i was gonna.
cause i have come up against people much better than me in player matches and if they don’t play ranked then they’re gonna not have the bp to reflect
The general consensus is that ALL of the skill matching in SF4 at this point is based on BP.
However, that MAY change when the Championship Patch DLC is released (should be March 31st, but you never know).
That is why its kinda important to play some ranked matches and see where you wind up in the grand scheme of things. Its true that there are droppers and boosters, but they are a minority. If you can get a few hundred ranked matches in, the system does a pretty good job of matching you based on skill.