>>56886567missed the last thread but that guy actually has good advice for people new to the game. to add on a bit, letting your opponent decide where damage is going is really bad for you. it's why cards like sabrina and x speed are so good.
starmie's 130hp is dwarfed by venusaur's huge 190hp, but how much health does each player have on the board at any given time? if each player has a full board and everything set up (which won't really happen, but still), how much of each player's pokemon's hp is being used? your opponent WANTS you to use the active spot as a choke point where you're just funneling all of your pokemon through one at a time to get ko'd.
venusaur, being kind of stuck in the active is pretty much using it's 190 and then dying. starmie can take a hit and then retreat for free- so that means starmie's hp + one benched pokemon's hp is actively engaged and usable in the game. starmie's health is getting 'extended' by the benched pokemon. If that pokemon is another starmie, then you have yet another pokemon whose HP is actively available and 'extending' the amount of HP that is in play and denying your opponent a point. you absolutely should be building your decks with a retreat strategy. make the damage requirement for your opponent to get a point as high as possible!