Yes, good points. My little list is of course not exhaustive, there are lots of other points and each sport probably has its own little details that add to home advantage. So everyone feel free to share your thoughts. I know most sports or watched them at least once in my life, but for example Cricket is something, that I have no, really no, idea about. So would be interested to hear, if in Cricket there are certain things, that add to home advantage.
1. On International games you are not going to suffer from Jet lag which can be a real issue especially when you are trying to perform at the highest level possible.
Yes, this could maybe be included in travel stress in general, but I have to admit, that I didn't have that one in mind. In Europe this is not that much of an issue, but already in the US when travelling from one coast to the other, it can be important (f.e. the NFL west coast teams playing at 1pm at the east coast). I remember, when Vladivostok was in Russian Premier League and the mostly in West Russia located teams had to travel there. It was a) a huge travel and b) some hours time difference. And vice versa, the Vladivostok team had to basically go on a world trip every two weeks for their away games
2. Depending on the game there are different sizes the field may have and still fall under the rules, so playing at home gives you advantage in the sense that you know perfectly the size of the field while the visitor may make several mistakes because the field is bigger or smaller than their own.
I know Barca has a huge pitch. It was intentionally designed as big as possbile to suit the playing style of them. In german Bundesliga you have Freiburg and the pitch in their stadium has some gradient (it's around 1m iirc), so for one half you would always have to play a uphill a bit.
3. The weather can be a big influence in the games especially if there is some kind of condition that the opposite team is not used to experimenting, for example teams that play in a warm weather may have problems playing in colder weather.
Yep, we can witness that very well every year in NFL. Carr doesn't like to play in cold weather f.e. and going to Foxborough or Lambeau in January is even more of a problem for a lot of teams than it normally is anyway.
4. The sea level can be a huge factor as well if it is really high and visiting players come from a place that is near the sea level, if the sport uses a ball then the ball will have a tendency to travel farther away and visiting players will experience fatigue faster due to the reduced levels of oxygen.
In the Copa Libertadores you have these teams from Ecuador (?) and Bolivia that have a huge home advantage, because they play on 3,000m+ altitude. It's extremely hard, even for way superior teams on paper, to play there, because they are just not used to it and struggle like crazy with their breathing.