I don't think this is really a pattern, it's more of a behavior. Over the years I have noticed that sometimes when the water is cold the bass will only hit a bottom contact bait once, then they back off. If you kill the retrieve and just let the bait sit there then the bass will come back after a few seconds, pick up the bait, and start swimming off with it. If you continue the retrieve after that first bite, then no more bites.