Return to the Strategy of... Battle Line

Dear all,

Since my original post on the strategy of Battle Line, many such games have come and gone. Greater exposure has inspired  many further thoughts, which I am now minded to share with you all. This article has been rather difficult to lay out, as the concepts at work tend to run into one another. I shall separate it into hand management, where to place, and when to place, and hope that this structure proves helpful. Again, the tactics cards will not be discussed here... though I have had thoughts on that subject as well...

Thinking about the contents of your hand

As discussed in the original article, one should always start by playing for a straight flush (since they can be easily converted to a straight or a flush), and play a higher-value (preferably centred around an 8) against a lower-value, or (if not possible) a lower-value (preferably centred around a 3) against a higher-value straight flush. From these considerations, the following definitions of cards in hand at the beginning of the game can be thought of in two ways:

High in value: higher cards beat lower cards with the same formation. That's easy to grasp. Slightly more subtle is the concept of...

High in probability: the chances of a successful formation being completed. At this beginning of the game, this refers to the likelihood that a straight flush is possible. Two cards of the same suit with adjacent values (henceforth a "double") are high in probability; provided that neither is a 1 or a 10, there are two cards which can complete the straight flush. By comparison, a "split" (i.e. two cards with a number in between, such as 7 and 9) require a single specific card to complete the straight flush; in short, there are fewer ways of completing the formation. (Note that this is also the reason why, considering single cards, an 8 is better than a 9; there are more ways to complete the formation around an 8, as it has three potential straight flush formations, whereas a 9 can only be in two formations.) At the beginning of the game, a double has a better-than-average chance of completing; a split has slightly less than a 50/50 chance (as cards still in the deck will be evenly split, but there are those in the opponent's hand, as well as those which will never be picked up, which reduces the odds of acquiring a specific card).

These considerations are crucial when deciding what to play in a certain position (given the priorities below). If one wishes to win a position where the opponent has already placed, it is generally best to play something higher in value (if possible); however, depending on the game state, you may decide you have better odds of success by playing something low in value but high in probability (i.e. if, given what is in your hand and already played, you think it is unlikely the opponent can complete their higher-value formation). By contrast, when playing to an open position, high in probability is generally better than higher in value.

The junk pile: At the beginning of the game, any card has the potential to form a straight flush. As the game proceeds, this will no longer be the case. Those cards which are no longer valuable for completing straight flushes should be considered separately - I call it the "junk pile", though that is rather glib, as these cards actually play essential roles. Specifically, they are the cards that will be used to fill out straights and flushes where the straight flush has failed, as well as collect three-of-a-kind to defeat the opponent's failed straight flushes. Thus the "junk pile" is really the second string, where unbroken straight flush cards as the first string. Try to keep track of which cards can be used to complete which formations!

Trash: finally, we have cards which cannot be used for any purpose. In practice, these won't accrue until the late stages of the game - until you have played cards to every position, and as least some of these are closed, most cards will still have potential (in the junk pile at worst). Cards only become useless trash when they cannot contribute to any hypothetical position. Trash cards have a single potential purpose - to demonstrate, where possible, that the opponent's formation cannot be completed (and therefore that you have won the position). Generally, try to keep them in hand until the opponent has lost the position, and then reveal by playing on a position with the lowest possible priority (you'll lose that position, so try to hold back until you can win essential positions by revealing the opponent's failure).

Placement priority

... that is, which are priorities to win (and hence positions where you will want to play high probability and value), and those which are lower priorities. These considerations mainly come into play when considering which open position to begin strongly, but may be relevant where a single card may be used in more than one active formation, or where timing is important. In practice, this will usually be a judgement call, and depends on the current game state, but I would generally prioritise positions in the following order:

1. Positions which win you the game (usually by breakthrough). This much is self-evident.
2. Positions which prevent the opponent winning, again usually by breakthrough. If an opponent has won two adjacent positions, you must prioritise winning one of the next adjacent positions to prevent their success.
3. Positions which will build towards a breakthrough. If you are strong in one position, try for the adjacent positions.
4. Positions which will impede your opponent's breakthrough; that is, play strong to an adjacent position, particularly if it fills the gap between positions in which your opponent is already strong. (At this point in the list, game state becomes increasingly important in choosing priority... depending on the board, your hand, and deductions about your opponent's hand, it may make sense to increase the priority of this).
5. Anything from here is a judgement call between playing against positions your opponent has begun, or opening strongly at positions where you may build towards a breakthrough.

When to place

Advice often given to beginners is that Battle Line has a second-player advantage, as the second player can choose the most relevant card to play after seeing what the first play has placed. I do not necessarily agree with this; sometimes, I believe it is better to choose to play to an open position, even when there is the option to play responsively. Of course, if you are the first player, you may have little choice; however, even when you are the second player, you might want to start a new position rather than responding to the first player. This is because, if you are lucky enough to have a starting hand which is strong (particularly in probability), it may be smart to establish a potential breakthrough position at the beginning. By the same token, if you only ever play in response to the opponent's starting card, you may end up giving away a breakthrough (i.e. by playing three lower-in-value cards where the opponent succeeds in delivering their higher-value formation). Thus, deciding whether to open a new position or play in response to the opponent is a judgement call based on your own hand and the opponent's placings. All I can offer as guidance are the hand considerations and placement priorities above.

On the strategy of Battle Line

My lords and ladies,

I have now had the pleasure of playing the excellent card game "Battle Line" three times. I have also had the frustration of losing the game "Battle Line" three times, against an opponent with only marginally more experience.

One does not become a gentleman gamer by allowing such a record to stand unchallenged, and consequently I took to the automated telegraph system vulgarly titled "The Internet" to determine how best to improve my play.

What follows is a synthesis of the strategies I discovered. At the time of writing, these strategies are untested by me, as my opponent has temporarily retreated to the Norfolk fens to engage in dark plans known only to himself. However, all writers on this topic are in broad agreement, so this guide may be taken to be a general synopsis of the thoughts of more experienced minds than my own.

Photo credit: Nagato Fujibayashi

Firstly: on the selection of which flag to place one's card

1. I am informed that Battle Line games are most often won by breakthrough (i.e. winning three adjacent flags) rather than reaching 5 flags. Thus this should be uppermost in one's placement strategy, whether thinking offensively or defensively.
2. In particular, the flags which are three spaces from the end are the most valuable and should be the highest priority. This is for two reasons. Winning these will limit the opponent's ability to win a breakthrough; i.e. winning flag 3 will make it almost worthless for the opponent to play for flags 1 or 2 as they can no longer break through at this end, while the winner may make a breakthrough anywhere in the range of flags 1-5. It also gives the winner of flag 3 the option to use flags 1 and 2 as either parts of a breakthrough or "dumping grounds" for less valuable cards.
3. It is generally best to play defensively, which is to say, reactively. Hence, in general, place cards against flags where the opponent has already played cards.
4. Following this logic, it is best to place where an opponent has already played two cards, thus revealing his or her strategy. One can then choose whether to play a competing strategy or to sacrifice that flag and use the spaces available on one's own side as a "dumping ground".
5. If (as will most often be the case) this is not possible, one must either react to a single card from the opponent, or attempt to take a strong position on an unstarted flag.

Secondly: general strategies for winning formations

1. Most flags, particularly against experienced opponents, will be won by either a straight flush (the highest-value formation) or three-of-a-kind. Always play with a view to obtaining one of these; if it is clear this will not be possible early in the play of a given flag, consider converting it to a dumping ground before that opportunity is lost. This is particularly true at the beginning of the game, so focus one's hand management on developing these two formations (particularly the straight flush).
2. Except as described below, strive for a straight flush. This is because, if it becomes impossible to complete such a straight flush, it can be converted either to a normal flush (with a non-consecutive card of the same suit) or a normal straight (by playing a consecutive card of a different suit), whereas a pair cannot be converted to anything useful if the third card is unavailable.
3. Following this logic, the best card available is an 8, and the next-best is a 3. An eight can be converted to any of the three highest-scoring straight flushes (8-9-10, 7-8-9 and 6-7-8), so it can immediately be seen to be strong. The strength of the 3 is more subtle, and requires understanding of another general strategy - do not start competing straight flushes. For

   

   Photo credt: Nagato Fujibayashi

   example, if you have a 4 and a 7 of the same suit, it would be disastrous to play both and try for straight flushes, as both will be competing for the 5 and 6. Instead you might consider either dumping one or using it in a three-of-a-kind, depending on cards revealed and in your hand (you might try for two non-competing straights, but you risk clogging up your hand if you wait on such an outcome). The strength of the 3 is that it is the centre card of the "low-ball straight flush", being usable in any of the 1-2-3, 2-3-4 and 3-4-5 combinations, none of which compete with the "high-ball straight flushes" centred around the 8.

Thirdly: choosing which cards to place at a flag

1. If placing a card where the opponent already has two cards, then your strategy is determined by those cards. If the opponent has a straight flush underway, they you will have to try for a higher-value straight flush if you want to win the flag. If you believe you cannot compete directly (based on the cards in hand and already played) then you must either use that flag as a dumping ground while you still can, or play a lower-scoring formation and hope that the opponent cannot complete their straight flush. If the opponent has a three-of-a-kind underway, then it is probably best to play for a low-ball straight flush, which beats any three-of-a-kind while preserving your own higher scoring straight flushes; otherwise, try for a higher-scoring three-of-a-kind.
2. If the opponent has one card, then you can form your strategy based around that card. In general (i.e. unless the information already revealed dictates otherwise), follow this strategy: (a) if the card is lower than an 8, play a higher card and try for a higher straight flush (b) if the card is an 8 or higher, play a lower card and either try for a three-of-a-kind and hope the opponent fails to get their straight flush, or try for a low-ball straight flush if they go for a three-of-a-kind.
3. If you must play to a flag with none of the opponent's cards (which you will, particularly if you are the first player), then "power-play" - try to place cards to win the flag as soon as possible, usually by starting with an 8. There are two reasons for this: one is that placing multiple cards on one flag may force the opponent to place first cards on multiple other open positions. The other is that, if a flag is won before the opponent can place three cards, then they are denied a slot which they could otherwise use as a dumping ground, and hence their flexibility is restricted.
4. Clearly, it is generally best to try a straight flush in a different suit to the opponent, to maximise one's own chances. The exception to this is when one can "break" an opponent's straight by doing so - e.g. if an opponent plays a 1, playing a 3 (or, if necessary, a 2) of the same colour makes it impossible for them to acquire a a straight, while preserving the possibility of a straight flush for oneself (albeit a harder one to obtain, with the 1 already out of play). If one's own straight is impossible, one still has the option of a three-of-a-kind which will still beat any formation the opponent can make with a 1.

Finally: the tactics cards

1. The hows and whys of tactics cards are less clear-cut than the above rules. As a general rule, it is best to hold off playing the first tactics card, as obviously gives away the momentum for the opponent to play up to two, while you may not play any until they do so. Consequently they could play just one and prevent you playing any more for the rest of the game.
2. Generally do not have more tactics cards in hand than you can play. If you have played yours and are waiting for the opponent to play theirs, do not fill your hand with dormant tactics.
3. The exception is at the beginning of the game. This is for two reasons: one is that the first tactics card you gain may define much of your early strategy, so you should consider drawing it early. The other is that an early tactics card can win a crucial early flag, which can be advantageous for many reasons as described above. Thus you should decide at the beginning whether to be one who plays a tactics card first or not, and draw early if you wish to do so (though only play that tactics card to win the flag if possible - otherwise you may lose it due to Deserter or some such).
4. The end-game also provides an exception - a very specific card may be necessary for victory, in which case drawing many tactics and hoping for a leader or other winning tactics card may be better than drawing troops (provided you can play the card, of course).

After digesting the points above from experienced players, I have high hopes for my next attempt.

Photo credit: Nagato Fujibayashi

Digested strategy tips

• play to win by/defend against breakthrough, using straight flushes centred around the 8 or 3 cards.
• flags 3 and 8 are the most valuable.
• try to lay cards reactively; otherwise, try to win the flag as soon as possible, starting with an 8 for a high straight flush if possible (and using Tactics cards if necessary).
• against two cards, play higher straight flushes against lower straight flushes; low-ball straight flushes against three-of-a-kind; and, against straight flushes you can't beat, either play three-of-a-kind and hope the opponent can't complete or dump cards now while you still can.
• against one card below 8, play a higher card for a higher straight flush; against a high card, play a lower card (particularly a 3) and play for a low-ball straight flush or three-of-a-kind depending on the opponent's second card.
• don't draw more tactics cards than you can lay (except maybe in the end game to win a crucial flag).