2 Never on a (Major) Sunday
When rain drenches a course to the point that standing water is an issue, all the major tours (PGA, LPGA, Champions, Nationwide, European) enact local rules that allow players to lift, clean and place their balls either near the resting place or within one club length to get relief. "It's absolutely the last resort," says PGA Tour rules official Mark Russell. The PGA Tour has been using such rules since the 1960s and the LPGA for almost as long, but they are organizations run by the players (in essence) and have to worry about a postponement disrupting the following week's schedule.
That's not a concern at the majors. None of the four men's majors have ever played lift, clean and place, although those rules were used at the 2004 Senior PGA Championship at Valhalla and the 2008 LPGA Championship at Bulle Rock.
The USGA has always been particularly adamant about playing it as it lays. At the rain-soaked 1996 U.S. Open at Oakland Hills, then director of rules and competitions Tom Meeks famously called the practice "lift, clean and cheat" and swore the USGA would never allow it. If a player's ball comes to rest in standing water, the USGA does permit him to lift and drop it at the point of nearest relief no closer to the hole, as allowed by rule 25.1b, but it does not issue a coursewide ruling that lets players pick up their ball after each shot.
3 Dirt + Water = Trouble
Pros love lift, clean and place because it allows them to wipe their ball, removing any of the mud that can make the next shot unpredictable.
It will make the ball go right but by how much is anyone's guess.
DOWN THE MIDDLE
On top, in the front or back, it creates a knuckleball effect.
It'll go left. As with the others, take an extra club, swing easy and pray.