In Spades, what should be the first card to play in a round? That is to say, what should be the open lead?

In the Bridge, this question was studied intensively, for example by The world of Bridge: Opening Leads. That source offer the following opening. My question is this opening as strong in Spades?

Of course different opening should be used to different rounds' types, assume a round with no Nil bids, and sum of bids of at least 10 (a.k.a round type: Over)

1. Top of a doubleton, such as 8 5 or A 3.

2. King from AKx, With AKT73, lead the king; take your tricks before declarer starts ruffing. Leading the ace would tell partner that you don't have the king.

3. King from KQx, such as KQ72, to set up a quick winner before declarer can ruff.

4. Top from solid or nearly-solid honor sequences, with QJT6 or QJ95, lead the queen; with JT983 or JT87, lead the jack, and so on. However, holdings such as QJ53 or T932 are not solid or nearly solid, so look for an alternative plan (see below).

5. Top from a three-card holding with no honors, such as 987 or 632.

6. Low from three cards including one or more honors that do not form a sequence. From ♦ QT6 or ♣ K83, lead the lowest card.

7. Fourth-best card from four-card or longer suits (with no solid or nearly-solid honor sequence). With QJ53, T963, KJ532, or 9873, lead the three-spot; with J97532, lead the five.

8. Usually, don't underlead an ace.

9. Top of an interior sequence.

• Much of those are conventional agreements in bridge; while some of those nonetheless arise from logical considerations, leading the top or bottom card from a number-card doubleton for example is pretty much up to your agreement with your partner. The idea is that if you lead an 8 and your partner wins, and returns suit, then you play a 5, your partner should expect you have only those two (or 4 or 6 but not 3 or 5).
– Joe
Aug 13 '18 at 19:22
• Agreed, Conventions are wildly use in Bridge, much less in Spades because bidding is simplified. However it is still possible to use some conventions. The conventions that I know are: 1. high-low doubleton (that you mention) 2. Big 5 bid (that signal: I can cover Nil). 3. Lead what partner first lead. Aug 14 '18 at 7:54
• Carding agreements are "conventional" the way Joe means it as they are generally agreed, by convention, by all players. However, they're not "conventions" the way you mean it, which do only apply in the auction. While there are better and worse leads from particular holdings, and better and worse holdings to lead from, the only bad system is the one partner isn't also playing. Hence, "by convention", there's a standard set of agreements, so that without discussion, you and partner will be reading the same thing into the plays. "Overloaded terms" strikes again. Jan 20 at 19:47
• @Mycroft, By convention, we mean a signal system that both partners agree upon. Jan 20 at 19:50

Found a nice answer in a Reddit thread by `byu/DiscreteMelody`

Many of these leading conventions are borrowed from Bridge, and for great reason - they work. Even though half of the cards are known in Bridge, we can still convey a great deal of information to partner on our leads. The following leading conventions are commonly used when the aim is to maximize tricks.

1. Top of a doubleton - Whenever you hold two cards in a suit, lead the top of the doubleton. Lead the 9 from 94 of hearts. Lead the T from T7 of diamonds. On the second lead of the suit, partner will see you complete this hi-lo signal and see you lack strength in the suit and you only held two cards.

2. Top of an honor sequence - Whenever you hold touching honor cards, lead the top of the series. For example, Q from QJx, K from KQ, or J from JT9. When we lead an honor card, we are promising to partner a singleton, or the next card in the sequence. If we lead a Q, partner knows we have the J. If you do not lead the top of the sequence, you will confuse partner. If you choose to lead the Q from KQ, partner might needlessly cut off your head with the A. The better the support, the better the lead. Leading K from KQJ is a lot stronger than leading K from KQ2.

3. Low from an unsupported honor - If you don't have touching honors, you can opt to lead low from an unsupported honor. Leading the 3 from Q43 promises partner that you have some strength in the suit. He will feel more confident offering up his K in 3rd seat if your West opponent does not rise with the A. Try to save these leads for when you hold a K or Q in the suit, but a J will also suffice if you don't have another desirable lead.

4. Top of nothing - Sometimes we do not have an attractive lead. We don't want to lead away from a tenace, and we don't want to deceive partner into throwing away a K, Q, or J by leading the 3 from 32 of hearts for example. In cases like these, leading top from nothing is a last resort. The 8 from 862, or the 7 from 7652.

• I would suggest that in lieu of Top of Nothing one adopts a more strict attitude approach. Lead high from small to discourage a return in that suit, and low to encourage a return in that suit. Thus way you lead Top of Nothing when you desire a switch, and low from nothing when you don't. I've had much better success with this approach in Tournament Bridge than with blind Top of Nothing. Also with the reduced information available in Spades, Third-And-Fifth best leads convey more count information than lowest or Fourth best. Jan 18 at 1:59
• @Not on the lead. As a basic principle all signals should be made as emphatically as the available cards allow, to help Partner's reading. After that one hopes the visible and played cards allow Partner to make the read correctly. In Bridge, when following low on first round of a suit the accepted practice is to signal count if Opponents led it and attitude on Partner's lead. All is relative. Holding 432: play of the 4 is a high spot; holding 654 the play of the 4 is a low spot. partner can usually make the read correctly, but playing either the 3 or 5 from those holdings asks for trouble. Jan 18 at 9:15
• In bridge, your partner looks at their hand and looks at dummy, figures out what cards are left, and uses that information to deduce whether you led one of your low cards or one of your high ones. This is harder in spades because your partner sees fewer cards. Some beginners at bridge who aren't yet capable (or, more accurately, can't devote the mental energy given all the other things they are trying to figure out) of deducing whether their partner led a high or a low card do make specific agreements about what counts as 'high' or 'low'. Jan 19 at 22:06
• Remember that the "traditional" opening leads, which are still pretty standard, come from Whist, and were settled before Bridge, never mind Contract, was a thing. Therefore, they should be effective in a similar full-deck, no-dummy trump game. But as always, they work best if both players in the partnership are on the same page, whatever that page is. Especially when combined with a signalling agreement. Jan 20 at 19:43
• Argh, I didn't see this. If all you care about is the actual leads, the ACBL Convention card has them marked. web2.acbl.org/documentLibrary/play/Conventional-Wisdom/… has some explanations as well as the lead section of the card. It also has different standards for leads against trump and notrump contracts (relevant in bridge, but spades never plays in NT). If you want explanations of why they're "standard", if you can get a copy of Watson's Play of the Hand, the two chapters on leads at NT and leads at trump are the best I've seen. Apr 16 at 21:35