A fungo bat is used by the coach to hit ground balls or fly balls to his team. All throughout high school and college many players use fungo bats to play fungo golf. This is when each person has a fungo bat and a baseball and they pick out targets around their field or complex and basically play it in the same manner as golf. Fungo bats should not be used to hit a pitched baseball because they are much weaker than normal bats and will break much much easier.
Though entertaining enough, this play appears in its entirety as a small part of Sorrentino's magnum opus MULLIGAN STEW. You can read it as easily there as in this form. Plus you'll have the rest of Mulligan Stew as well. So I recommend you only buy this volume if you're the sort of collector who owns books because of what they are, not what they say.
For starters, we should clarify just what we’re talking about when we say fungo bat. Longer, lighter and thinner than a regulation bat (but a larger barrel), a fungo bat is typically 35 to 37 inches long, and weighs between 17 and 22 ounces. As David Allison wrote in the June 1978 edition of Country Journal, “A fungo bat looks to be a cross between a baseball bat and a broomstick.”
This sounds like a lot of information, but with a little practise on the coaches part, it runs quite smoothly. Two to three reps per player in the field per section is quite adequate, and with 14 men on the field, this whole routine should take about 7 minutes. It's quite snappy, and quite impressive. I had many a parent marvel to me after witnessing it - "you look like a professional team!" I wouldn't try the routine with anything less than a 14 yr old select team, but with the talent to do it right, it's fantastic.
Once in a while, veteran managers revive it. The Giants took infield occasionally in 2008 and 2013 under Bruce Bochy, and Jim Leyland instituted infield drills before batting practice late in his tenure in Detroit. Molitor, for one, misses it. He took infield even as a designated hitter late in his career because he hated sitting around for almost two hours waiting to play.