Update Chart.js

Adição de labels:
var infoFighter1 = {
    data:{
        radius: 45,
        labelsColor: '#999',
        segmentShowStroke : false,
        segmentStrokeColor : '#fff',
        segmentStrokeWidth : 0,
        percentageInnerCutout : 70,
        animation : true,
        animationSteps : 100,
        animationEasing : 'easeOutQuart',
        animateRotate : true,
        animateScale : false,
        onAnimationComplete : null
    },
    info:[
        {
            value: 100,
            label: 'striking',
            labelColor: '#fff',
            color: '#e02f3d'
        },
        {
            value : 100,
            label : 'submissions',
            labelColor: '#fff',
            color : '#ad1d28'
        },
        {
            value : 100,
            label : 'takedowns',
            labelColor: '#fff',
            color : '#454545'
        }
    ]
};

var fighter1 = new Chart(document.getElementById('stat').getContext('2d'));