All esports tournaments are cast to the public with a time delay. Usually the delay is 5 minutes. The reason is so that players cannot gain advantage by watching the cast and know what the other team is up to in real time. It is an understandable practice, especially since most tournaments are online and LAN tournaments are more uncommon. On the other hand, most esports bets are in-play. The odds makers therefore have a 5 minute advantage on their customers.
The time delay
From the perspective of tournament organizers having a delay is necessary. It removes a big area of potential cheating. There are operators who receive the stream without delay, and some that receive it with a delay. So far it has been a revenue stream for tournament organizers to sell priority access. There is also the same issue with the actual game statistics and data. Some operators do offer the direct stream to their customers, and there is also a possibility of getting access to the data from the game without the actual video stream, which gives the savvy esports bettor an equal footing.
There are two reasons why betting operators do not want to supply real time access. First, the time delay is a buffer which protect them from advantage plays. It also helps protect against other problems connected with cheating they want to avoid no matter the situation. The second reason is simply the huge advantage it is to have a 5 minute head start in setting odds.
Esports bettors disadvantage
Esports betting is an emerging market. Therefore, there are still plenty of room for profit both for the operator as well as the punter.
The problem with few operators is comparing odds is difficult, which is one of the main advantages for a punter. In-play betting further exacerbates the situation. Furthermore, it is not always clear who the odds provider is for a specific site, as many operators share both data and traders. Thus even if you do compare, you might be comparing like for like, and not be aware of it due to the 5 minute time delay combined with normal odds fluctuations for in-play games.
The best you can do as an avid esports fan and esports bettor, is to be aware of the time delay. Use your own analysis of the current game situation, while aware of the time delay, when you place your in-play bets. Also remember that odds analysis is far from solved by the operators, so there is still a lot of value to be had for the savvy punter.
Good luck, and have fun!