The usual approach against pushing teams is an aoe-heavy turtle-lineup.
You get the idea
Prevent them from pushing your rax as long as possible, give your carry/ies the maximum amount of farm, then wait for their next big push, genocide them and get a pair of barracks yourself.
Have your ranged carries snipe down Polly's wards as quickly as possible, the aoe will take care of pushing creeps. Have your PK/blink-gankers//even take out their squishies as fast as possible to cripple their push even further. Continue to farm.
If you make it past the 45 minute mark you will usually win.
Last edited by EspritFort; 07-02-2011 at 10:44 PM.
some heroes are good at countering pushes. behe, pyro, soulstealer, soul reaper, etc. heroes who can nuke waves down fast
another idea is to have one hard carry freefarming in your short lane/jungle and maintaining creep equilibrium after his tower is pushed. you need to ward your jungle/their tower to protect him from ganks though