At the start of the game try to get first blood for your team, one rocket grab can be a sure kill, it is a priority if you want your AD carry to get the advantage.

This is good for jungle invading too, try to zone people out in the early laning phase, as they will be scared by your grab, then work with your AD carry to try and pick up kills as you out level the enemies.

As the laning phase ends there will be a lot of action in mid lane, try to pull enemies through walls and pick them off one by one.

When chasing someone make sure you activate your ultimate as late as possible as it will do more damage over time.

The best blitzcrank combo is to pull, knock up, chase and then continue to know them up, pulling them back if they are faster.

You can also use your pull to disrupt enemies like Katarina, stopping them from outputting damage, this means if they are being carried hard you can shut their carry down.

Note: The statistics shown at the top do not take into account the passive of manamune for some reason unknown to me, but the damage should be a lot higher.