波比的Valiant FighterValiant Fighter tooltip can be misleading. 50% damage reduction only applies to the portion of damage that actually exceeds 10% of Poppy's current health, not entire damage of that attack. Example: Poppy has 1200/2000 health and is being hit by a 400 damage nuke (after resistances). She will then take: 1200*10% regular damage plus (400-10%*1200)*50% reduced damage, which will total in 120+140=260 damage taken.
When chasing an enemy, remember that it is often easier to ram them into a wall with Heroic ChargeHeroic Charge and stun them than attack them when you catch up to them. Maneuver to the side of them so that the charge will bring them into a wall.
Heroic ChargeHeroic Charge stuns when pushing an enemy champion into surrounding terrain, also included in "terrain" are towers. Even after a tower is destroyed, the rubble leftover is still included as "terrain." Nexuses and inhibitors are also terrain.
Heroic ChargeHeroic Charge can be used to charge across impassible terrain, so long as it is in between you and your target. This is usually unexpected and a great way to either jump an enemy who flees too closely to a wall when you are on the opposite side, or can be used to charge to neutral minions on the other side of a wall in the forest, to escape. Keep in mind that you must have vision of the target, and thus this isn't often possible when chasing an enemy by yourself.
The 8% bonus damage from Devastating BlowDevastating Blow causes the skill to scale well with your opponents Health up to some threshold based on skill Rank. At Rank 1 the 75 damage threshold is reached when your opponent has 937.5 health (687.5 * 8%).
Buying a Philosopher's Stone is a must on any Poppy who intends to roam. Poppy scales exceptionally well with regeneration due to her Valiant FighterValiant Fighter ability, and the passive gold gain on the item allows her to somewhat make up for the gold that she is missing out on from minion kills.
When building AD Poppy, you will still able to do considerable damage to heavily armoured foes as your Devastating BlowDevastating Blow turns your next attack into full magical damage which is not affected by any reduction from armor.
Beware of Poppy's late game potential if she manages to farm up gold. Poppy is one of the most powerful late game champions in the game and can sometimes kill several members on your team during Diplomatic ImmunityDiplomatic Immunity's duration. Thus, denying Poppy farm will have a huge impact on her effectiveness. One good counterpick as lane opponent is Olaf who can sustain while dealing a large amount of true damage which bypasses Valiant FighterValiant Fighter .
Ignite is the easiest way to kill a low life Poppy, since her passive makes her otherwise extremely resilient against magical and physical damage.
One common strategy used by Poppy is ulting the support (since supports have the least damage output), and then focusing the enemy carry. Support champions with good CC such as Janna can help counter this.
But in general, picking a team which have a lot of CC waiting for Poppy whoever she uses her ulti on will have a dramatic impact on her performance in teamfights, no matter the role of the champion.
Due to 波比的Valiant FighterValiant Fighter, she is naturally strong against burst champions, such as Kennen or Akali. Rather than sending one of these champions to lane against her, have a magic damage DoT-centered champion like Malzahar or Swain lane against her, effectively shutting her down. She has no magic resistance per level, making them very efficient counters against her.