AngularJS Two binding in directive

Problem: I have a controller that gets an array of players, and presents them to the user. These player have a set of stats that a user can then incremented or decremented, since a player can have multiple stats, and I want them to behave the same, so I am creating a directive that has a number and 2 buttons "+" & "-". When the user clicks "+" the value should go up, when the user clicks "-" the value should go down. The goal with this directive is to make it easy to tweak the template and have that reflected everywhere, the directive is also trying to be stat agnostic, that way it can be re-used for several different stats. The user can have selectedPlayer, this directive will be bound to a stat on this selectedPlayer. The issue I am running into is if I change the selectedPlayer the directive doesn't seem to update with the new selectedPlayer, or the new value from the directive doesn't seem to actually update the selected player.

Code may help explain this better.

<div class="h3 text-center">{{title}}</div>
<button class="btn btn-lg plusMinus-btn btn-danger" ng-click="statCtrlr.statDown()">-</button>
<span class="stat-val digits md vcenter text-center" style="width: 50px;" ng-cloak>{{statCtrlr.statValue}}</span>
<button class="btn btn-lg plusMinus-btn btn-success" ng-click="statCtrlr.statUp()">+</button>

the js (.ts actually) file:

var app = angular.module("stat-val", []);

app.directive("statVal", () => {

    return {
        restrict: 'E',
        templateUrl: 'templates/statValue.html',
        //transclude:true,
        scope: {
            title: "@",
            data: "=" 
            //prop:"="
            //statValue: "=val",
            //statCol: "@col",
            //plrid: "@plrid",
            /*plr:"=plr"*/
        },
        controller: ['$scope', '$http', function ($scope, $http) {
            //$scope.statValue
            var ctrl = this;

            //ctrl.statValue = $scope.data[$scope.prop];
            console.log("$scope", $scope);


            ctrl.statValue = $scope.data;

            console.log('stat-val::$scope', $scope.data, $scope, ctrl.statValue);
            //console.log($scope.$parent.entryCtrlr.selectedPlayer.plrid);


            this.statDown = () => {
                console.log("statDown", ctrl.statValue);
                if (ctrl.statValue > 0) {
                    ctrl.statValue--;

                }
            };

            this.statUp = () => {
                console.log("statUp", ctrl.statValue);
                ctrl.statValue++;

            };
        }],
        controllerAs: 'statCtrlr'
    }
});

how is its being called in html

<div class="col-xs-3 no-gutter">
     <stat-val title="FGM" data="entryCtrlr.selectedPlayer.stats.fgm" prop="fgm"
     ></stat-val>
</div>

The json data that gets used:

player: [
{
 stats: {
  fgm: 0,
  fga: 0,
  fgm3: 0,
  fga3: 0,
  ftm: 0,
  fta: 0,
  tp: 0,
  blk: 0,
  stl: 0,
  ast: 0,
  min: "",
  oreb: 2,
  dreb: 4,
  treb: 6,
  pf: 0,
  tf: 0,
  to: 0
},

},

Update

console dump:

Your $scope.data is two-way binded, not ctrl.statValue:

this.statDown = () => {
    console.log("statDown", $scope.data);
    if ($scope.data > 0) {
        $scope.data--;
    }
};

this.statUp = () => {
   console.log("statUp", $scope.data);
   $scope.data++;
};