In the past, when there were 30 or 34 rounds, the middle of the season (15 or 17 rounds) was before New Year so half season was exactly that - half season. That's why the winter champs were those who were leading the standings at half season. Now things got fucked up with more matches being played during the season. Still, the winter champs are imo those who lead the table at half season (19 rounds).
