The pitcher giving up the last to balls gets "credited" with the walk.
Yes
he could have made a balk ... walked the batter or hit him with the ball ...
Yes, the player is credited with a RBI.
In baseball statistics, a base on balls (BB), better known as a walk, is credited to a batter and against a pitcher when a batter receives four pitches that the umpire calls balls. It is called a "walk" because the batter is then entitled to walk to first base, or more specifically (as defined in the rules of baseball) he is "entitled to first base without liability to be put out." Any baserunner who is forced advances as well. Receiving a base on balls does not count as an official at bat for a batter but does count as a plate appearance. A pitcher can also choose to intentionally walk a batter. This is usually done for the purpose of facing a different batter that the team feels they have a better chance of getting out, or to allow a double play possibility if first base is open with less than two outs. A hit by pitch is not considered a walk, though the consequences are often the same for both.
Home rune, steal home, Balked in the the pitcher, Walked in with bases loaded, by the batter hitting a single, Sack file, Run down between third and home, passed ball by the pitcher or catcher
When the hitter is either hit by the pitched ball, or if the pitcher throws four balls in a row, then the batter may proceed to go to first base because he has been walked.
When he is walked.
If the pitcher throws four balls to one batter, it means that the batter would get a free base. However, the ball is not dead. For example, if the fourth ball was a wild pitch, other runners could advance, including the runner who had just walked.
I have seen answers that range from 75% to 85%, but you can't go by those kinds of odds. Odds in baseball are completely different than, say, poker or craps. With poker, you always have 52 cards in a deck and the number never changes. With craps, the dice faces never change. In baseball, your odds are determined by the abilities of at least six (Pitcher, Catcher, Batter 1, Batter 2, Batter 3, Base Runner on second) and up to thirteen (the remaining fielders) or more (Batter 4 if one of the other batters is walked) players. Just some factors: Is the pitcher on his "A" game? And even if so, is he an ace or mediocre? The batting averages of the upcoming batters. Are any of those batters hot or cold? If NL, Will the pitcher be batting? What are the fielding percentages of the players behind the pitcher? Will the pitcher intentionally walk the next batter to try and create a force-out situation?
not for the pitcher
This happened in the Caribbean baseball league a number of years ago. One of the managers took exception with a call that the home plate umpire made and refused to allow his pitcher to pitch the ball to the following batter. After waiting for a couple minutes, the umpire instructed the pitcher to pitch. The manager told the pitcher not to. the umpire then started calling balls. "Ball one.....ball two.....ball three....ball four, take your base. Next batter. Ball one...." Quickly the manager got off the field and allowed his pitcher to pitch.
Anytime a batter is walked it does not count as an at bat