Simple and fast vanilla js event delegation. Uses Element.closest and falls back on @readable/closest fast polyfill. In case better browser support is needed, use slower and more primitive Element.closest polyfill.
Element.closest polyfill is required only for IE, other reasonably up to date browsers are fine without it.
npm install --save @readable/delegate<script src="node_modules/@readable/closest/closest.js"></script>
<script src="node_modules/@readable/delegate/delegate.js"></script>Rd.delegateEvent(document, 'click', '#counter', function (event) {
this.innerText += 1
})<button id="counter">0</button>