4. Team A and Team B each send out 7 players to participate in a Go chess tournament in a predetermined order. Both sides start with their No. 1 players competing. The loser is eliminated, and the winner then competes against the No. 2 player of the losing side, ... until all players of one side are eliminated, and the other side wins, forming a match process. The total number of all possible match processes is
4. Let the members of Team A be $a_{1}, a_{2}, \cdots, a_{7}$, and the members of Team B be $b_{1}, b_{2}, \cdots$, $b_{7}$, where the subscripts indicate the predetermined order of appearance. The competition process can be represented by these 14 letters interweaving and being arranged in sequence, indicating the order in which they are eliminated. However, the last one must be the remaining member of the winning team and any members who did not participate, so the competition process can be represented by choosing 7 positions out of 14 to arrange the members of Team A (of course, the remaining positions are for Team B members). The total number of competition processes is $C_{14}^{7}=3432$.