Slippage direction

I've yet to trade live so i'd like to get some insight from experienced traders.
I was wondering if slippage usually happens in the direction of the market or is it erratic? (assuming market orders)
In other words, if i trade a breakout going long would the slippage be in the direction of the trade, hence working against me? while on the other hand, if i went long on a pull back the slippage would be downward so it would work in my favor?

You can't predict how you are going to get slipped, if you want to control the entry price use limit orders.

If you have a reputable broker and learn the right times to trade, this problem will seldom occur.

Slippage almost never happens when I trade. If it does, it isn't something impossible to overcome. It will typically occur in the direction of the current candle or last few candles, however you will typically get filled more quickly if you enter in the opposite direction of the immediate candle. See how the two forces counteract each other if you enter in the opposite direction of the current candle?