Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Sivir the tanker raper
I think its good to use the defense masteries with a squish champ
ricochet for minions farm and damage on the beggining
i dont use boomerang to much cause cost to much mana
spell shield its good to have.
exhaust to 1x1 fight vs a melee champ
ignite important vs mundo, ww or if the champ is running
meki pendant you need because ricochet
phanton dancer its good to increase your mov. speed and critical chances
infinity edge itsthe perfect iten to do damage with crit
you need madred to take a tank down
frozen mallet its good to slow targets