A third baseman is chasing a base runner back to second base.
The people are playing a ballgame.
A third baseman and a base runner could be people.
exists e1 s1 s2 x1 x2 x3 x4 x5.(Theme(e1,x2) & Actor(e1,x1) & v_chase(e1) & to(x4,x5) & n_base(x5) & a_second(s2) & Theme(s2,x5) & back(x2,x4) & n_thing(x4) & n_runner(x2) & of(x2,x3) & n_base(x3) & n_baseman(x1) & a_third(s1) & Theme(s1,x1))
exists e1 x1 x2.(n_people(x1) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_ballgame(x2))