I searched on Google and found many interesting quotes, however, this one caught my attention, because it is simple, short and it is something I believe we all can agree on. I am leaving the name of webpage where I found this quote, in case any of you want to check it out.
"This was my first lesson about gambling: if you see somebody winning all the time, he isn't gambling, he's cheating. MALCOLM X
Source: notable-quotes
Agree, it is eternal truth. Because one of the main characteristics of gambling is that there will be losses along with win. If a person wins consistently then it is definitely suspicious. He may win 5-6 bets in a row but after that he will definitely lose. If some one would lucky then his wining ratio can increase but it doesn't happen all the time. But consecutive wins will usually reflect cheating. Because defeat is a very common feature in gambling.