I definitely understand Ferries better now.
Okay, so I thought I would try writing down some of my thoughts. I suspect the ideas I have so far are pretty well known, but maybe somebody in 2031 will find this useful ...
The Basic "Steal"If an opponent has a valuable road and you get a ferry, you can join the opponent's road in one turn (unlike the usual "place a meeple this turn and connect it next turn" sequence). It looks like this when Yellow joins the valuable Red road:
Of course, Yellow is not guaranteed to benefit from this, because the ferry can move again, but I think this play is almost always the best thing to do in this situation.
The Double ScoreThis one surprised me. If you have a valuable road, and you draw a ferry, I think your best play is to connect the ferry tile to the existing road, but don't simply extend the road: instead, put a meeple on one of the new road ends, and then connect the two docks that
don't connect to the valuable road! This will close the valuable road (in this case, Red immediately scores 8 points and removes the meeple on the completed road):
The idea here is that on a subsequent turn, you can complete the newly created road and shift the ferry back to the valuable road, scoring even more points this time (in this case, Red scores 10 points)!
Note that after this play, the ferry can never be moved again, because the only open dock does not have a ferry. Also note that although an opponent can prevent the double-score, they cannot "re-steal" the road by immediately (that is, in one turn) by placing a meeple on a regular tile, because your meeple is already occupying that road:
Probably the best play for an opponent in this case is the defensive move of placing the tile without the meeple and moving the ferry, permanently closing the valuable road so that you can't score it again:
Although defense is probably the best play with a regular tile that completes a road, there is a risk that the opponent will draw another ferry tile, in which case they can immediately take possession of the valuable road segment:
After this move, the original ferry (top of image) can never be moved again. The second ferry is still movable, so Yellow's advantage here is not permanent, but it will take Red multiple turns to prevent the steal.
I’m especially interested in ways to combine multiple ferry tiles in interesting or unexpected ways....I’m wondering if I might end up losing out on something that is really cool
The answer to my original question is definitely YES! Having many ferry tiles definitely changes the risk-reward balance of going for the double-score! More ferry tiles makes this play more risky!
Other SituationsI'm still working on understanding the best plays in more complex situations. But I think the basic insights described here have helped me understand and enjoy Ferries a lot more. I hope I'll learn more and post again sometime soon.
As always, questions or comments welcomed. It is difficult to be sure you haven't overlooked a logical flaw when you are only playing against yourself!