First of all, you must be prepared to not convince them.
These Liverpool fans, they are a bitter lot. They are like the kid who was making the pretty girl laugh at the party and just as they were going to make their move, the handsome, popular guy asks her for a dance and she leaves him and glances bakc with a look that says "you made me laugh, but I wanna have this guy's babies and be banged so hard I can't walk tomorrow"..
what were we talking about again?
oh yeah, ok so you need to take a higher ground. First you throw your stance out there
"What?! Robbie Keane is good, but Berbatov is so much better. Way better. he's in a different league."
Then you must let them talk. Don't interrupt. They will try to sucker you in. Oh yes they will, but thou shalt resist."
Be chill!
If they try to sucker you in, just ask them to tell you all that's good about Robbie keane.
Once they're done, you start. You hit them where it hurts.
You start with his control. They might make some noises, but in their hearts they know it's true. berbatov's first touch is magnetic.
You say that, then you say heis touch is so good it often looks like the ball is glued to his boot. Keane's touch is heavier. Berbtov's is a much more delicate and softer touch. more skillful. he caresses the ball.
Then the movement with the ball. Keane, you say, is a good athlete (always the sugar first), but he is workman like when he runs with the ball. (then the spice)
Berbatov, you say, is graceful, almost like watching a ballet dancer.
Then you talk about skill. Have they seen Robbie Keane do a skill like Berbatov against West Ham, there will be silence followed by an attempt to digress.
You steer them back, like a matador taming a bull.
You say, "No, no. let's talk about skill. Has Keane produced flashes of brilliant skill like that?"
They will try, but they will fail.
Finally you talk about goals.
You say, Berba had a better goal per game ratio at Spurs and has a better goal per game ration at United than keane at Liverpool.
http://en.wikipedia.org/wiki/Robbie_Keane
http://en.wikipedia.org/wiki/Dimitar_Berbatov
They might say Keane helped Berba score those goals, you will say likewise.
Then you will say "You can talk all you want about preference and work rate, but in terms of first-touch, ball control, dribbling and output, Dimitar berbatov is clearly better that Robbie Keane!"
OR YOU COULD JUST SAY, SHUT THE **** UP YOU LIVERPOOL-SUPPORTING, UNDER-ACHIEVING BITTER, BITTER ****S. DIMITAR BERBATOV IS BETTER THAN ROBBIE KEANE, BECAUSE HE PLAYS FOR MANCHESTER UNITED AND NEVER GOT ROBBED!