Copyright (c) 2001 László Nagy

Push 4 is played on an empty 7x7 square board.

PUSH - On each turn, each player place a stone on an board edge and the stone is immediately rolled one position onto the board to push the existing balls before itself.
A stone cannot be pushed, if a row or column is full (stones do not go off-board)
GOAL - Wins the player that achieves a 4 in-a-row (orthogonal or diagonal)
An example

Black's move. He should push down on column d and wins next turn. If White tries to prevent by pushing down another stone on d, Black wins with another push down in column d, making a vertical 4 in-a-row with stones d2-d3-d4-d5.

There is a ZRF to play Push 4 with Zillions. A variant of this game, called Roll 4 by the same author, states that a stone inserted on the edge rolls as many empty cells as possible (until it finds a stone or the opposite edge), instead not pushing. Both games have hexagonal variants: Roll 4X and Push 4X.

An Roll 4 example

White's turn. He has a winning sequence, starting by rolling a stone into cell [1]. The remaining moves are forced.