Re: bjj vs wrestling which one is more effective?
Both arts are effective because they specialize in their particular range. Wrestlers will always be stronger with takedowns and control whilst jiujitsuan will always have the edge in submissions.
In answer to the direct question of which one is more effective in MMA - I would say wrestling beause I believe the standup rules, time limits and points system lends itself to the wrestler's strength who merely has to score a takedown while the jiujitsu figther wants the submission. I personally believe jiujitsu is stronger in a gi and in street situations involving normal clothing - but inside the ring - the gi advantage is taken away.