never draw to an inside straight

今天看Growing Pains看到了这样一句短语never draw to an inside straight，影片翻译为“做人要口是心非”（DVD）或者“千万不要在左边开车”，感觉有点奇怪。Google了一下，原来是扑克的术语：
That's a straight where you need one of the cards in the middle such as when you're holding 4 5, 7, and 8 and you need a 6. What they're saying is if you need an inside card to complete a straight, fold rather than pursue it. That's because only one card (actually four if none is already dealt) will complete your straight. If you're working on an "outside" or open-ended straight there are two cards (actually eight if none is already dealt) that can complete your straight - either the card to complete it at the beginning or the end. In other words, you have double the chance of completing an outside straight than an inside straight.
简单地说也就是如果你的顺子缺的是中间的一张牌的话就不要博了，因为几率太小，如果缺的是边上的牌子，则几率大了一倍。