It's all about the hover, reports the WSJ:
--Wait in a place where you can see at least 20 parking space in front.
--Assume that the average person's mall trip is roughly three hours (180 minutes). Divide by those 20 cars and probability factors indicate that one of those cars will leave in nine minutes or less.
--The more cars you watch, the shorter the wait. Lingering in a place with 25 parked cars could shorten the wait time to about seven minutes.
--Don't watch more than 25 cars. Even if you are able to see a car pulling out of a spot farther away, you probably won't be able to beat another driver to it.
As for where to look, the Journal advises a row that's equidistant between mall entrances (spaces near the entrance are most likely to be full).
*More secrets from Roy Rivenberg some years back in the LAT:
What's the best strategy for finding a parking place? Should you grab the first spot you see or cruise the lot for a space closer to the store? According to a scientist with too much time on his hands, it's faster to park in the first available stall. By applying probability statistics and "discrete-time semi-Markov chain mathematical logic" to a Wal-Mart parking lot in Virginia, researcher C. Richard Cassady, now a professor at Mississippi State University, proved that you can get into the store a few seconds sooner if you pick a row and take the best spot available, even if it's at the far end of the lot, according to a report in U.S. News & World Report. Drivers who circle around looking for a space closer to the store cut their walking distance by 27%, but that's canceled out by the longer time it takes them to park.