Chess Openings Pro

Chess openingsReview details:
App version: 4.1.1
Device:  iPad 3
Operating system: iOS 9.3.1


A well designed and valuable tool for club players wanting to brush up on their general opening play though it may be somewhat limited for more in-depth study of particular openings 

Chess Openings Pro is an iOS app from Tom Ashmore for use on tablet and mobile devices.The Pro version of the app, as it’s name suggests the fully featured edition and costs £2.99. There is a free trial ‘Lite’ version (Chess Openings Explorer) which has some important restrictions which are outlined where relevant in this review. It is also worth saying, don’t confuse the Lite version of this app with the similarly named android app (reviewed here). They are developed by different people and are independent apps.

COE_mainChess Openings Pro as its name suggests, is a tool for exploring and learning about the chess openings. The app enables openings to be studied in a range of different ways several ways; it does this primarily in two ways using:

  • information from a database of opening moves which is drawn from the results of a large pool of games;
  • an integrated chess engine to provide detailed analysis of specific positions and the option to play out games from openings of the user’ choice.

A database of moves with associated frequencies of wins/draws/losses (w/d/l) is a commonly used format in established chess database applications. The app is not particualy innovative in that it uses the well established approach of  visually representing opening move choices in the form of a ‘tree’ of individual moves from the current board position. These moves are shown with associated ‘performance’ information relating to the move such as the number of times it has been played, and the scores in terms of game outcomes (For example 50% of games playing the move from this position where won by white… etc).  But it ain’t broke don’t fix it – this is an effective approach as it enables the user to quickly see which are the most frequently played moves from a given position and what the also which produces the best results.


An app dedicated to chess openings is only really as good as the database it uses. The volume and quality of the games are key factors to consider:

  • too few games and the database is too small to give sufficient information about individual moves or coverage of opening moves. (for example you can’t conclude much if there are only the results of says 5 games from the current position!)
  • if the database is made up of games between weak players or games played at very fast time controls (eg bullet or blitz) the quality of the moves played will generally be low and the results in terms of the game outcomes (w/d/l) will be similarly impacted (garbage in garbage out)

COEPro2Chess Openings Pro stacks up pretty well in terms of its database. The Pro version uses over 1.9 million ‘high level’ games. Whilst ‘high level’ is not defined, at least the importance of quality is recognised and the volume is good enough that it doesn’t feel that positions are reached too quickly where there are no games left . (Note the database in the Lite version is a third of the size). One specific feature which is rare to find in this type of app but which would be valuable is the ability for the user to import their own database of games to use for the move tree – this would allow the user to make their own choice  (for example using only games played between players above 2500 elo etc) – sadly Chess Openings Pro doesn’t give the user this option either.

The Pro version (but not Lite) helpfully includes an engine to provide analysis in positions where there isCOE_engine_output no tree available. This is a valuable feature allowing for independent study particularly in less popular lines, where for example the opening tree may run out of games only a few moves in. The user can play the opening against the engine or use it to analyse specific positions. The engine analysis is clear and includes all key information such as evaluation, suggested move and optimal line of play (principal variation). It’s not all good news though as there are a number of niggles that if resolved would increase the app’s practical use. For example:

  • there’s no option to set or influence the analysis time  – a best move will be suggested or played at a certain fixed 12 ply depth  (analysis will however continue beyond this if play option is disabled as in the image above)
  • there is no multi-pv option available, which is an important  feature for analysis purposes (multi-pv allows an engine to analyse and display more than one move at a time – for example the best two or three moves in the current position). This is helpful for example when trying to assess the merits of different possible moves
  • the engine used isn’t identified so it is difficult for the user to gauge the quality of the analysis and how much reliance to place on it


The app has a range of additional learning features which are of varying practical use. Probably the most significant of these is the quiz mode where the user can test their openings knowledge by answering a range of multiple choice questions. These can be selected based on your own preferred openings (which can be saved separately) or randomly generated.

The quiz mode is a fun and potentially useful exercise  and a % score is awarded at the end of the test. However, some of the answers and comments appear rather contrived and/or inappropriate – for example it makes little sense to tell me I have chosen the least popular move if all 5 moves available have only been reached in a total of 7 games! In reality,  I suspect the real benefit to this option will lie in testing yourself against your own preferred openings rather than the classic quiz which throws an apparently random assortment of openign positions at you.

There is also an Opening of the Day option, which on selection presents what appears to be a random opening position with associated database analysis. And that’s about it. In short it’s not clear what the point of this specific option is other than perhaps to introduce users to new openings.

Taken together it is likely these features could leave the user with a rather dissatisfied feeling  – whilst it may be interesting to see a broad range of opening positions and also be useful to develop some broad awareness – the reality is I’m not likely to be playing or facing many of these openings. I suspect the average player will be wanting to develop an in-depth knowledge of a much narrower range of openings. For example,  if I only play d4 and have the caro-kann as my defence of choice as black to e4 then I’m not interested in the complexities of the Sicilian or Ruy Lopez. Of course the opposite could be argued also and the app may be useful in stimulating the user to find and try out new, perhaps even ‘offbeat’ openings and variations.

Practical use and presentation

The app is well designed and easy to use. All options are clearly identified and accessible from a single screen. Additionally, the app’s chess engine can easily be engaged at any point by a simple swipe. The developer has clearly given useability some thought and this is shown in several small but nice touches. This includes for example use of a small coloured pawn to clearly indicate which side the engine thinks is ahead and an ‘Opening Book’ option  which allows the user to access and set up the board with any opening and variation however obscure, at the touch of a button.

Visually the app is appealing having a clean and uncluttered appearance. The chessboard and pieces are clear and easy to view – no awkward colour clashes of garish colours. The only slight disappointment is that there is no ability to alter the default options to add some variety.

Developer support

Chess Openings Pro is an app that is in active development with a history of regular releases. Updates have provided bug fixes and improved functionality. The developer is available via an email address which is readily available either from the app store or within the app itself. Whilst easy to use, the app also has an element of built in support, via a simple help button, which covers the basic operation of the app.



  • Simple to use
  • Good visual presentation
  • Large database of games
  • Inclusion of chess engine for self-analysis


  • Inability to import/load alternative database
  • Engine used is not identified
  • Opening of the Day seems a bit pointless


There are some additional more detailed notes about this app in the Developer notes section.

These are my thoughts; if you have used this app what do you think…..





9 thoughts on “Chess Openings Pro

  1. I’m the OpeningTree author so naturally I have some bias in commenting on Chess Openings Pro but i’ve been looking closely at the books of Chess Openings Pro and also another app that shows in roughly the top three results of search of chess openings on iPad/iPhone Chess Openings Explorer Pro.

    OpeningTree databases now 200,000 both over 2300 games. Chess Openings Pro has 2 million high rated games and Chess Openings Explorer Pro had 3 million as it claims Grandmaster games.

    To be honest i’m not clear how Chess Openings Pro defines high rated. Are the games over the board high rated or are they an internet collection. He does say the 2 million are recent games which lends some weight they could be internet games as its hard to find 2 million recent high rated games over the board. A friend who is a master commented some openings played are not played by masters. He gave me this line which he says is a common patzer opening: e4 e5 nf3 nc6 Bc4 Bc5 d3 h6. OpeningTree has no games after the move h6. Chess Openings Pro has over 100. Chess Openings Explorer Pro also seems to have no games.

    Now Chess Openings Explorer Pro with its 3 million grandmaster games is interesting. Two things I noticed. One is how do you find that many qualified grandmaster games? Are they just over 2500? But that aside may not matter as much and the book appears to be good quality. But to find 3 million grandmaster games the app needs to use games I would think over many decades. And what this does is make the book a bit of a historical book. OpeningsTree is pretty much all post 2010 what is played and a modern book. I suspect Chess Openings Explorer pro has a lot of older games from previous eras and would not be as reliable in finding current modern play always. Now which is better is up to the user. Kings gambit isn’t played much in modern high rated play but users may want a good solid set of choices to explore in that opening.


  2. This review on chess openings pro is very good and solid and i also read the developer comments section. adding this last comment actually because i forgot to check notify me of new comments in my last 🙂


  3. For reference I did some searches to see how common e4 e5 nf3 nc6 Bc4 Bc5 d3 h6 is in Big Base 2018’s 7 million games. The position before h6 comes up over 2000 times searching both players over 2000. With h6 and both players over 2000 searching all 7 million games it comes up only 34 times. Both over 2100 it comes up 13 times. Both over 2200 it comes up 5 times. Both over 2300 it comes up 2 times. In last two searches the 2 and 5 results all games are from the 90s and not recent games.

    Now I don’t want to seem to say Chess Openings Pro’s book is necessarily bad as a result of finding over 60 games with h6, but it appears to me to perhaps be internet games. This can be valuable for some people who simply want to see what is played in any opening they know not necessarily a master openings. And as the reviewer says the high number of games give more credibility to the first few choices. However as you get into lines I wonder if by mixing some patzer games in the quality of the results could be less certain.


  4. I was born year of the Dog, This might be kind of the year of the Dog in me 🙂 barking at something suspicious, raising warnings 🙂 But again as I mentioned it can be a great database to find any opening anyone plays.


  5. I dont want to boost d4 nf6 c4 e5. We are at 113 games i think now and its a sort of ok sample size if you consider with both games over 2300 results of say 5 games are meaningful. But i’d like to get up to 300K or 400K games databased over the next few months. Even with current technology its a bit time consuming but i can schedule it in over a longer time span to be a bit less tedious and not done in 5 days. i got 150K in in 5 days i can in a few months i think get to 300 or 400 total. And this will keep me honest and help everyone in a similar situation. But the kings gambit i suspect needs a different treatment as its not a modern opening anymore.


  6. I may be mistaken in assuming chess opening pro is an internet database. I researched its change log on the Itunes preview page in the browser and this apparently is the criteria it used “Games are only included if one player is rated above 2200 ELO.”. Now having some experience with chess engine book building this can be ok if you have two books. A white and black. The games show as moves only from the stronger players side such as if the 2200 is white as whites responses to a patzer but you never see blacks moves because they dont make the black book. In a single book situation its not so great to include patzer games against masters as their low rated responses get databased in in the same way as the strong responses to.


  7. I dont think its intentional. i think it’s a novice mistake of chess openings pro to include patzer master games in a single book not a white and black. If this was a chess engine book it would be a flawed book. You dont want to fetch a chess move if your an engine and get a patzer move because a game with good moves for white was databased in but now you’re black. That is why its important in book building when building one book not a white and black both sides be strong. Book building isn’t necessarily a novice game and I learned about it well before doing opening tree during the period i developed my Pulsar Chess Engine.


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