15. (12 points) Two students, Xiao Wang and Xiao Li, are playing the game "Rock, Paper, Scissors." The game rules are: winning a round earns 3 points, drawing a round earns 1 point, and losing a round earns 0 points. The game consists of seven rounds. The player with the higher score at the end of the game wins.
(1) If Xiao Wang's final score is 10 points, what are the results of Xiao Wang's seven rounds of the game in terms of wins, draws, and losses?
(2) If Xiao Wang's results for the first three rounds are one win, one draw, and one loss, what results does he need in the remaining four rounds to ensure he beats Xiao Li?
Three, 15. (1) Let Xiao Wang win $x$ times and draw $y$ times $(x, y$ are natural numbers). Then
$$
\left\{\begin{array}{l}
3 x + y = 10, \\
x + y \leqslant 7, \\
03(4-x-y)+y, \\
x+y \leqslant 4, \\
0 < x \leqslant 4.
\end{array}\right.
$$

Solving, we get $(x, y)=(4,0),(3,1),(3,0)$,
$$
(2,2),(2,1),(1,3) \text{.}
$$

Therefore, Xiao Wang winning four times, winning three times and drawing once, winning three times and losing once, winning two times and drawing twice, winning two times and drawing once and losing once, or winning once and drawing three times can all ensure a win over Xiao Li.