This tactic is only used against Zerg.Because the aim is killing Zerg Overlords as much as possible to harm the enemy economics and macro.Here the important point is keeping balance of air units and ground units carefully because if you can not keep balance of units the enemy can destroy your defenses easily by his outnumbered cheap Zerglings or Hydralisks.So you must construct some cannons at your defense and near your Nexus to prevent any Lurker,Mutalisk or high numbered Zerglings.Then send your first corsair to the enemy base which will start killing overlords if the enemy is not well prepared this tactic will be very helpful for winning the game at the later stages or near stages of the game.If he is prepared this attack type you can group your fleeet and use them more plan based and carefully to slow down the enemy unit production.After some new technology developments you can upgrade your fleet by Distruption Web ability to overcome ground targets especially Acid Spores and groups of Hydras.