The Spanish La Liga enters its final day of the season with the relegation battle grabbing most of the attention, involving Deportivo La Coruña, Celta Vigo, Real Zaragoza and Real Mallorca.

All four teams have a home match to help them with their chances. Deportivo host Real Sociedad, who are fifth and have a chance to make the Champions League if they win while Valencia mess up; Celta face Espanyol, who have nothing to play for; Zaragoza play Atletico Madrid, who are third but are also without any real motivation; and Mallorca, in the most problematic of situations, playing Valladolid, who are also without any goal standing before them.

The La Liga uses the head-to-head system to decide its tie breakers, which is very likely to come to use as only two points separate the four clubs. If two teams are tied, it’s decided like their matches where a two-legged knockout stage, with the away goals rule applying. If three teams have the same amount of points, a mini-table is created with the head-to-head results in their six matches being used. Only Deportivo, Zaragoza and Celta can create such a situation which has any significance, with Deportivo finishing on top thanks to goal difference.

17	Deportivo La Coruna	37	6	5	7	23	25	2	6	11	24	44	-22	35
18	Celta de Vigo	37	6	6	6	22	21	3	1	15	14	31	-16	34
19	Real Zaragoza	37	5	4	9	22	24	4	3	12	14	35	-23	34
20	Mallorca	37	6	5	7	22	28	2	4	13	17	42	-31	33

All teams get the same result – no change. Deportivo remain in the Spanish La Liga, the rest are relegated. Regardless of the other results, if Deportivo win their match against Real Sociedad, they will be the surviving team.

If Deportivo draw, things get a little bit more complicated. If they draw and the three other teams don’t win, Deportivo still stays in the top flight. A draw, accompanied by a Mallorca win while Zaragoza and Celta don’t win their matches, still means Deportivo remain in the top flight thanks to their head-to-head record with Mallorca. In fact, the only team they lose to in their head to head is with Zaragoza, which means that a Zaragoza draw, Deportivo loss, Celta loss and Mallorca not winning keeps Zaragoza in the top flight.

Both Zaragoza and Celta can remain in the La Liga, at the expense of the other, if they win their matches and Deportivo loses or draws, with Mallorca’s result becoming insignificant at that time. Celta have the head-t0-head edge with Zaragoza, beating them twice this season. A draw is enough only for Zaragoza, and only in the case Deportivo loses and Celta & Mallorca don’t win thei matches, as we mentioned above.

For Mallorca, it’s pretty simple. They have to win their match against Real Valladolid, a team with nothing to play for, while hoping that Deportivo loses and the other two teams don’t win. Any other combination means relegation for Los Bermellones after 16 consecutive seasons in the top flight.