JSFiddle - React, Tailwind, and code Playground

JavaScript

function g(a,s){
    x=1;
    for(i in s){
        if(x<=a){
            $('body').append('Round ' + (+i+1) + ' ' + s[i] + ' - ' + a + (s[i]=='W'?' + ':' - ') + x);
            s[i]>'L'?
                (a+=x,x=1):
                (a-=x,x*=2);
            $('body').append(' = ' + a + '<br />');
        }
    }
    return a;
}
$('body').append(g(15, 'LLLWLLLL') + '<br />');  //1
$('body').append(g(20, 'WLLW') + '<br />');  //22
$('body').append(g(13, 'LLWLLLLWWLWWWLWLWW') + '<br />'); //7