First, it looks like you're expecting the yi variable to match not only his latest chat message but also whether he's winning, which is just totally unrealistic. Second, calling the variable "yi" invites problems in mirror matches, OFA, that sort of thing. Third, the second if statement is at the same level as the first, so this could result in you asking "you sure I should believe you?" when yi is losing but hasn't even said anything.
Finally - although this is more of a style thing - the variable we want to check in a comparison is generally the left operand, while the value we're comparing it to is on the right. Doing this the other way around (as in "if (winning != yi)") reads awkwardly and is colloquially known as a "Yoda condition" due to sounding backwards, like Yoda speaks.
However, sometimes this is used intentionally when the compared value is a literal, to avoid the class of bug where you assign a new value to a variable rather than simply comparing the two when you accidentally use the assignment operator instead of the desired comparison operator. For example, if you want to see whether a variable is set to "hello", the statement "if (var = "hello")" would silently do the wrong thing while "if ("hello" = var)" would immediately crash, which is much easier to notice and fix.