Introduction

• Differences between betting styles, pre-flop and post-flop play 
• The relevance of top pair, variable bets, stack sizes and position
• What influence tracking software stats have
  
• How big is the expected profit?
  

When playing Fixed Limit you are used to placing small bets up to and on the flop, and big bets (2 small bets = 1 big bet) on the turn and river. This particular betting behaviour means that certain moves have become habitual, as the given odds are usually the same and only vary depending on the number of opponents. As a result, pre-flop play can be depicted in charts that help you play an optimal game, as you can't make any mistakes when it comes to the odds.

This regulated betting behaviour also clearly comes into effect in post-flop play of course. It's practically impossible to drive out a flush draw on the flop, as this draw almost always has the right odds. The same goes for the turn. On the other hand, you are aware of the fact that a hand that has assumed showdown value costs you a maximum of 2,5 big bets in a heads-up game if you're playing way ahead/way behind.

Mathematically speaking, many mistakes can be avoided here, and so you can come close to playing an almost optimal game (definitely preflop, but also postflop). This is the big difference compared to No Limit Hold'em.

When playing No Limit Hold'em all these points cease to apply, as there are no regulated bet sizes. This means that every one of your opponents is free to bet as much as he wants (this also means he can go all-in at any time). So your opponent can change the odds –both pre-flop and post-flop– in his favour. The following explains the consequences of this, as well as what further points you should take into consideration. 

Basic differences

It's hard to say in which format it's easier to beat a fish, and depends on your skills in the different game formats. But consider the advantages if a fish joins your table:

• It's easier to isolate him by using variable bet sizes
  
• You can rid him of his entire stack with one hand
  
• You can force him to make lots of mistakes
  

Use the opportunities you get to always give your weak opponent the wrong odds or use hard value betting with strong hands. Calling stations are particularly suitable for these measures. You don't need to use a lot of tricks, but you can force your opponent to pay much too high a price for his possibly weak hand, by making high value bets. You can't do this when playing Fixed Limit! You can use a maximum of 2.5 big bets post-flop as value bets in Fixed Limit, as long as your opponent only calls down.

Profit expectation is very hard to evaluate. It is generally said that if you've mastered a format, the profit you can expect to make is about the same. But due to fishiness and the number of available tables, which are discussed in more detail below, the expectation for No Limit is probably a little higher actually. 

What about variance? It's not very easy to answer this question, because it depends on how you look at it. If you consider how often you really win with the strongest hand pre-flop or on the flop, then Fixed Limit definitely has more variance.

This is related to the fact that you can't protect your hands sufficiently and so you will be drawn out on relatively often. When playing No Limit, on the other hand, you can often invest a lot of money with some very narrow decisions. 

It is, for example, quite possible to lose more than 5 stacks (500 big blinds) in one session, without you having made a big mistake. So if you take big blinds into account when looking at variance, you will find that you can attain bigger swings when playing No Limit. 

This is definitely a relatively big advantage in No Limit. The selection of tables – especially at the higher limits – is considerably nicer in No Limit than in the Fixed Limit area. You can find plenty of tables – at the higher limits too – at any time of the day. 

Additionally, the amount of fish decreases considerably at the high limits in the Fixed Limit area. A game doesn't become really profitable until at least one fish, who will often make exactly those mistakes that bring in money for you, is playing at the table.

There are also plenty of opportunities at the highest limits, whereas you'll really have to look for these when playing Fixed Limit. This has to do with the fact that the No Limit game is publicly the best-known format. In other words: many new players who pay a fee and want to get started at the higher limits immediately, prefer to play the format that they know from the adverts or from TV series.

Having stats on your opponent represents a huge advantage of course. It means you won't have to look at every played hand and internalise it. You'll be able to just look at the corresponding values from time to time as and when you need them for a reason. But there is one crucial difference in the analysis of statistics. In Fixed Limit you can analyse whether an opponent is playing strong over the long term by looking at certain values. For example:

• If the VPIP is too high, your opponent is making a lot of mistakes over the long term because he plays marginal hands too often and doesn't possess the necessary equity for the showdown. 
  
• If the PFR is too low, your opponent is making a lot of mistakes over the long term because he is not extracting enough value with his supposed strong hands while he is ahead.
• If the "Went to Showdown" value is too high, your opponent is going to the showdown with weak hands too often
  
• ...

You can continue this list as you wish. You can't draw the same general conclusions from these values when it comes to No Limit, however. A player with the values 13/10 (VPIP/PFR) can be just as successful a player as one with 40/35 or even 40/10, as long as his post-flop play is accordingly adapted.

Because of the greater betting possibilities on later streets, pre-flop mistakes don't necessarily indicate whether someone is playing well over the long term. There are also many players who play more passive and try to take as many hands as possible to the showdown. You can't automatically say that a high WTS value is always to be evaluated negatively here either. 

You can usually win more StrategyPoints (of course this varies from platform to platform) when playing Fixed Limit, insofar as you project this onto the number of played hands. On the other hand, you have to take decisions on the turn and river that demand more concentration because of the "showdown bound" factor in Fixed Limit games. This means that No Limit gives you the possibility to play a few tables more, which in turn means you can catch up to Fixed Limit in terms of StrategyPoints.