Talks a mean stick

Similar to "All hat,no cattle" but more urban in application. To brag about yourself or pontificate on how to do something you know very little about.
Originates from poolhalls where someone who sits on the sidelines and constantly explains how he'd make each shot if HE were playing. In reality,he couldn't get a ball in a pocket if his life depended on it.

"Ron wants us to get this repair done today"
"That can't be done in that time!"
"Ron says he can do it in a day."
"Well,Ron sure talks a mean stick"."