Google Analytics tracking for HTML 5 video player
I would use a single bind:

$("#videoplayer").bind("timeupdate", function() {
    var currentTime = this.currentTime;
    if (currentTime &gt; 0.75 * (this.duration)) {
        a = a + 1;
        console.log("watched 75%");
        ga('send', 'event', 'Videos', 'Watched 25%', 'Video 1');
    } else if (currentTime &gt; 0.50 * (this.duration)) {
        b = b + 1;
        console.log("watched 50%");
        ga('send', 'event', 'Videos', 'Watched 50%', 'Video 1');
    } else if (currentTime &gt; 0.25 * (this.duration)) {
        c = c + 1;
        console.log("watched 25%");
        ga('send', 'event', 'Videos', 'Watched 50%', 'Video 1');
    }
});


Unless there's a specific reason for you not to?