Mostly matches are Draw at MCG from last few years since there is not much help for bowlers there , still Batting 1st might be advantage to get result for both teams.
Last time mcg pitch gets bellow avarage rating by icc because of draw and slow track .after 3 day ball gets realy low not much bounce turn is on the pitch
Bro because of crowd pulling and 26th is boxing day so large number of crowd come to see match and mcg is bigger ground than brisbane and in this time chance of rain in brisbane than melbourne