Stay in the center of the ring, tie him up the instant he gets inside, make it a brawl if you have to and understand when he is transitioning from offense to defense. Don't pull a Judah by pulling that Fred Sanford shit he did in round 6 or 7, don't pull a Mosley and hurt him but then sit back, admire your work and then fail to get off. Don't pull an Ortiz and go super Mario, don't pull a Cotto and let up off the gas. Don't do a Maidana and throw punches with your head down. He's fighting a southpaw, so keep your feet in the right place, parry the jab with the right hand, move to the right throw the left at will.
It's hard to talk about Manny's defensive responsibility without shading back to his offense...since his defense is kinda like his offense. He will throw off speed punches, put them in your face just to keep you busy so you won't throw. I'm not on the same page that says Pacquiao has poor defense like most I just think that Manny's wanting to mix it up sometimes jeopardizes him. Sometimes his offense is his defense.
Yeah...if Manny can keep himself off the ropes and use his bob and weave style to make himself a harder target for Mayweather's jab then Floyd will take a little longer to time Pacquaio...this will make Floyd hold his "lead right attack" until Mayweather can properly draw a bead...the longer Manny can throw off Mayweather the better because Floyd doesn't unleash at the beginning until you've been time.
Manny has to remember that when he "breaks" from a hold with Mayweather to keep his guard up for the left hook...Many fighters get hit in a very small space because Mayweather is so quick and only needs a fraction of separation to pop you...it happened to Ortiz, Mosely, Gatti. They thought they were safe so they relaxed when breaking out of a hold from Floyd but he cracked em as soon as that very small space opened up.
At times Pacquaio will need to remain low like he did with Marquez at the beginning of the 4th fight (like Tyson) and not be so upright because as I stated before Floyd is going to shoot the jab up and down. Pacquiao will have to abandon the high guard defense he uses to block jabs when he is being backed up because it will expose his stomach and that is what Floyd will exploit. So rather than block he should slip and keep his eyes on Floyd.
If Mayweather presents his Philly Shell defense Pacquiao should move away from Floyd'd right and crowd his left hook while keeping his right guard high. Pacquiao will have to dip to Floyd's left not just move laterally so it will present a harder target for Floyd's leaping hook.
All in all...Pacquiao is in a terrible situation because if he goes all out trying to chase Mayweather, Manny is not technically sound enough to do that against Floyd and will get caught like Hatton. Throwing inaccurate punches in bunches is not good either because once you slip or block two punches from a fighter and you are in close range...you want to counter right after the second punch...you have the advantage. There are a lot of responsibilities Manny has to adhere to throughout a 12 round fight...so Pacquiao will have to hope that Mayweather starts to fade so that Manny himself can start to open up. Brawl Mayweather and your doomed...box Mayweather and your doomed.
Ring behavior: Manny can't clap his gloves together after he gets hit...because he is verifying to the judges that he was indeed hit cleanly...adjusting his trunks is also a habit after he gets hit (see Diego Corrales)...don't make the judges job easy to give points to the other fighter.
In the end a good BIG man beats a good LITTLE man...the boxing gods spoke this and it has held true more times than not. Floyd wins easy work.