Strategy Definitions

17 Frongello strategies, 12 experimental variants, and Phase Switch

Decision Framework

Every strategy in this study follows a common decision flow. On each dart, the player evaluates a short priority list to determine which target to aim at. The flow, in priority order, is:

  1. Chase (if enabled): Close the highest-value target your opponent has closed that you have not. This blocks their ability to score on that number. Not all strategies use chasing; when disabled, this step is skipped entirely.
  2. Score or Cover decision: Compare your current point lead to a threshold derived from the lead multiplier parameter.
    • If your lead is less than or equal to the threshold: SCORE — aim at the highest-value target you have closed that your opponent has not. Every hit past 3 marks earns points equal to the target's face value.
    • If your lead exceeds the threshold: COVER — close the highest-value target your opponent has not yet closed. This denies them future scoring opportunities and progresses toward closing all 7 targets.
  3. Extra darts (if enabled): On darts 2 and 3 of a turn, if the current closing target cannot be finished this turn (marks needed exceed darts remaining), redirect those darts to scoring on your highest closed target instead. This salvages darts that would otherwise make only partial progress on a close.
  4. S1 special case: Strategy 1 bypasses the score/cover decision entirely. It always closes targets in descending order (20, 19, 18, 17, 16, 15, Bullseye) and never scores until all 7 targets are closed. It then scores on whatever the opponent has not yet closed.

Scoring-Lane Fix

When in SCORE phase with nothing currently scoreable (no target is closed by the player and open by the opponent), strategies need to close a new target to create a scoring opportunity. In this situation, they prefer targets the opponent has not closed — creating a scoring lane — over targets the opponent has already closed. Chasing opponent-closed targets is a last resort, since closing them only blocks the opponent without creating any scoring avenue.

The Three Parameters

All 17 Frongello strategies are defined by three parameters. Every strategy is a unique combination of these values.

Parameter Description
Lead Multiplier The score-lead threshold, expressed as a multiple of the highest unblocked target value. None means always cover (S1 behavior). 0 means score until you have any lead at all, then immediately switch to covering (S2 behavior). 3, 6, or 9 require increasingly large point cushions before covering — for example, with 20 still open, a 3× multiplier demands a 60-point lead before switching to cover mode.
Extra Darts When closing a target that cannot be finished this turn (marks needed exceed darts remaining), redirect the remaining darts to scoring on your highest closed target. This prevents wasting darts on partial closing progress.
Chase First priority: close any target your opponent has closed that you have not, starting with the highest value. This blocks the opponent's scoring opportunity on that number. Frongello found that chasing is generally suboptimal.

Frongello's 17 Strategies (S1–S17)

Master Parameter Table

Strategy Lead Multiplier Extra Darts Chase Group
S1 — (always cover) No No Cover Only
S2 0 No No Basic
S3 No No Basic
S4 No No Basic
S5 No No Basic
S6 0 Yes No Extra Darts
S7 Yes No Extra Darts
S8 Yes No Extra Darts
S9 Yes No Extra Darts
S10 0 No Yes Chase
S11 No Yes Chase
S12 No Yes Chase
S13 No Yes Chase
S14 0 Yes Yes Combined
S15 Yes Yes Combined
S16 Yes Yes Combined
S17 Yes Yes Combined

Strategy Groups

S1 — Cover Only Baseline

The simplest strategy. Close targets in strict descending order: 20, 19, 18, 17, 16, 15, Bullseye. Never score until all 7 targets are closed. Once all targets are closed, score on whatever the opponent has not yet closed.

S1 serves as the baseline strategy in every tournament. It is predictable and entirely defensive — it never builds a point lead during the closing phase. Against strategies that score early, S1 frequently falls behind on points and must rely on closing out first to win. Its simplicity makes it a useful reference point, but it is rarely competitive.

S2–S5 — Threshold Variants Basic

These four strategies introduce the score/cover decision. They differ only in how large a point lead is required before switching from scoring to covering.

S2 (threshold = 0)

Score until you have any lead at all, then switch to covering. Even a single point ahead is enough to trigger cover mode. This is Frongello's optimal strategy among the original 17 — it balances offense and defense effectively. By requiring only a minimal lead, S2 avoids over-investing in scoring while still ensuring it never covers from behind on points.

S3 (threshold = 3×)

Score until your lead exceeds 3 times the highest unblocked target value. At the start of a game with 20 still open, that means building a 60-point cushion before switching to covering. This provides a moderate safety margin against opponents who score back.

S4 (threshold = 6×)

Require a 120-point lead (when 20 is the highest open target) before covering. More aggressive scoring means more time spent on offense, which delays closing but builds a substantial point buffer.

S5 (threshold = 9×)

Require a 180-point lead before covering. Very aggressive scoring. The risk is oscillation: the strategy can alternate between scoring and covering as the lead rises above and drops below the high threshold, wasting darts on mode switches rather than making steady progress.

S6–S9 — Extra Darts Extra Darts

These strategies mirror S2 through S5 in their threshold behavior but add the extra-darts redirect. When you are closing a number and cannot finish it this turn (marks needed exceed darts remaining), redirect those remaining darts to scoring on your highest closed target instead.

The extra-darts mechanism salvages darts that would otherwise make only partial progress on a close. For example, if you need 3 marks to close 19 but only have 1 dart left in the turn, that single dart aimed at 19 gains just one mark toward closing. Redirecting it to score on an already-closed target (say, 20) earns immediate points instead.

  • S6 (threshold = 0, extra darts): S2 logic plus extra-darts redirect.
  • S7 (threshold = 3×, extra darts): S3 logic plus redirect.
  • S8 (threshold = 6×, extra darts): S4 logic plus redirect.
  • S9 (threshold = 9×, extra darts): S5 logic plus redirect.
S10–S13 — Chase Chase

These strategies mirror S2 through S5 but add chase as the highest priority action. Before evaluating the score/cover decision, the player first checks whether the opponent has closed any target that the player has not. If so, close it immediately, starting with the highest value. This blocks the opponent's ability to score on that number.

Chasing is a reactive, defensive maneuver. Frongello found that it is generally suboptimal because it forces the player to close targets in the opponent's preferred order rather than their own. Instead of proactively choosing which numbers to close, the chaser responds to the opponent's actions, often at the cost of tempo.

  • S10 (threshold = 0, chase): S2 logic with chase priority.
  • S11 (threshold = 3×, chase): S3 logic with chase priority.
  • S12 (threshold = 6×, chase): S4 logic with chase priority.
  • S13 (threshold = 9×, chase): S5 logic with chase priority.
S14–S17 — Combined Combined

The combined group enables both extra darts and chase. These strategies represent the full parameter space — every mechanism turned on simultaneously.

  • S14 (threshold = 0, extra darts, chase): S2 with both mechanisms.
  • S15 (threshold = 3×, extra darts, chase): S3 with both mechanisms.
  • S16 (threshold = 6×, extra darts, chase): S4 with both mechanisms.
  • S17 (threshold = 9×, extra darts, chase): S5 with both mechanisms.

In practice, the combination of chase and extra darts does not produce a synergistic improvement. Chase diverts darts to defensive closing, and extra darts redirects some of those same darts to scoring, partially undoing the chase priority. The combined strategies tend to perform comparably to or slightly worse than their chase-only counterparts.

Experimental Strategies (E1–E12)

These twelve strategies extend the Frongello framework with ideas not explored in the original paper. E1 through E4 each modify S2 (the strongest Frongello strategy) with a single additional mechanic. E5 through E8 explore hit-type selection. E9 through E12 combine multiple mechanics.

E1 — Early Bull Experimental

S2 logic with a modified closing order. Instead of closing Bull last, close it right after 17. The full closing order becomes: 20, 19, 18, 17, Bull, 16, 15.

The rationale is that Bull is worth 25 points — higher than any number except 20. Under the default order, Bull is closed last, which means its scoring potential is never realized during the main game. By closing it early, the player creates a high-value scoring avenue that can be exploited if the opponent does not close Bull promptly.

Bull Sensitivity Warning

E1’s advantage is entirely dependent on bull accuracy. Under the standard model (bull = same difficulty as numbers), E1 tops average rankings at 9 of 11 MPR levels. But when bull difficulty is reduced to 0.75× (reflecting its smaller geometric area), E1’s win rate drops by an average of 5.67 percentage points — collapsing from #1 to dead last at MPR 3.6 and above. No other strategy moves more than ±1.3pp. This makes E1 the most fragile strategy in the entire catalog. See Bull Analysis for details.

E2 — Honeypot Experimental

S2 logic with a covering twist. When the strategy is in cover mode and has a point lead, it skips the highest target it can currently score on. That target is left open deliberately as a future scoring trap.

If the opponent later catches up on points, the player already has a ready-made scoring avenue — the target it intentionally left open. This sacrifices immediate closing progress for a strategic reserve of scoring potential.

E3 — Greedy Close-and-Score Experimental

Exploits the moment a target is closed mid-turn. When the player closes a number on dart 1 or dart 2, they immediately score on that freshly closed target with any remaining darts. The opponent has not yet had a turn to respond, so the closed target is temporarily an exclusive scoring opportunity.

After the turn ends, normal S2 logic resumes. The greedy element is purely opportunistic — it capitalizes on the information advantage of knowing a target was just closed before the opponent can react.

E4 — Adaptive Threshold Experimental

The lead threshold scales dynamically with game progress rather than remaining fixed throughout the game.

  • Early game (many targets unclosed): threshold = 3× the highest unblocked value. Score aggressively like S3 to build a point lead while many targets remain available.
  • Late game (few targets remaining): threshold approaches 0. Cover quickly like S2 to close out before the opponent can respond.

The formula is: multiplier = 3 × (unclosed_count / 7). With all 7 targets unclosed, the multiplier is 3.0. With only 1 target left, it drops to approximately 0.4. This creates a smooth transition from aggressive scoring to aggressive covering as the game progresses.

E5 — Smart Aim Experimental

S2 logic but adapts the hit type to the number of marks needed to close a target. When only 1 mark is needed, aim a single (96% reliable at pro level). When 3 marks are needed, aim a triple. When 2 marks are needed and it is the last dart of the turn, aim a double.

The insight is that triples are high-risk, high-reward: they close 3 marks at once but miss more often. When you only need 1 mark, risking a miss on a triple is wasteful — a single gets the job done with near-certainty. Smart Aim matches the dart selection to the situation.

E6 — Always Single Experimental

S2 logic but always aims singles (except Bull, which is always double). A control experiment that trades scoring power for maximum consistency. Every dart lands with ~96% reliability, but each hit only contributes 1 mark or 1× face value in points.

Spoiler: it is terrible. The consistency advantage cannot compensate for the dramatically reduced scoring throughput. Closing takes 3 darts per target instead of 1, and scoring produces a fraction of the points per dart. E6 exists primarily to quantify how much triples matter.

E7 — Always Double Experimental

S2 logic but always aims doubles. A middle ground between E6 (always single) and the default triple-everything approach. Doubles contribute 2 marks per hit and score at 2× face value, with reliability between singles and triples.

E8 — Score Triple, Cover Single Experimental

Aims triples when scoring (maximize points per dart) but switches to singles when closing or covering (maximize reliability of making progress). The logic is that missing a scoring dart wastes an opportunity but missing a closing dart wastes tempo — and tempo matters more when you are trying to shut out the opponent.

E9 — Phase Shift Experimental

A three-phase approach that shifts behavior based on how many targets remain unclosed.

  • Early game (5+ targets unclosed): threshold = 3×, scoring aggressively like S3. Many targets remain, so building a point lead is the priority.
  • Mid game (3–4 targets unclosed): threshold = 0, standard S2 behavior. Balance scoring and covering.
  • Late game (1–2 targets unclosed): pure cover mode. Just close out — the game is nearly won.

Unlike E4 (Adaptive Threshold) which uses a smooth formula, E9 uses hard phase boundaries for sharper behavioral shifts at critical game stages.

E10 — Score Surge Experimental

S2 logic with a mid-game scoring surge. When 3 to 5 targets remain unclosed, the lead threshold doubles to 2× the highest unblocked value. In all other phases, the threshold is 0 (standard S2).

The idea is that mid-game is the best time to invest in scoring: enough targets are closed to have scoring avenues, but enough remain that the opponent cannot close out quickly. The surge builds a point cushion during this window, then reverts to tight S2 play to finish.

E11 — Kitchen Sink Experimental

Combines phase shifts, smart aim, and the honeypot mechanic into a single strategy. The everything-bagel approach.

  • Phase shifts: Early game (5+ unclosed) uses a 3× threshold, mid game (3–4) uses 0, late game (1–2) always covers.
  • Smart aim: Adapts hit type to marks needed when closing (single for 1, double for 2 on last dart, triple for 3).
  • Honeypot: When covering with a lead, skips the highest scoreable target to preserve it as a future scoring avenue.

E11 tests whether combining multiple individually beneficial mechanics produces a stronger whole or whether the interactions create conflicting signals.

E12 — Finish Opponent-Closed Experimental

S2 logic with a targeted closing optimization. When behind with nothing scoreable, instead of opening a new target immediately, E12 first checks whether any opponent-closed target is exactly 1 mark away from being closed. If so, it finishes that target with a reliable single before moving on.

The rationale: one reliable single permanently stops the opponent’s scoring on that target. Opening a new target requires 3 marks (typically a triple or multiple darts), during which the opponent continues scoring on their open lane. By finishing the cheap close first, E12 eliminates the bleeding before investing in new scoring opportunities.

Phase Switch

The Winning Strategy

Phase Switch is the overall strongest strategy at the highest skill levels (MPR 4.0+), ranking #1 in the round-robin tournament under realistic bull difficulty. It outperforms S2 (the best Frongello strategy) from around MPR 3.4 upward, with its head-to-head advantage growing to +5.2pp at pro level. At lower skill levels, E2 (Honeypot) leads the rankings under realistic bull conditions — a notable shift from the standard-bull results where E1 (Early Bull) appeared dominant but was inflated by unrealistically easy bull hitting.

Two-Phase Design

Phase Switch divides the game into two distinct phases with a one-way transition between them:

Phase 1 — Aggressive Scoring (Early Game)

Use a very high scoring threshold: 13 times the highest unblocked target value. This means the player keeps scoring until their lead is enormous — a 260-point cushion when 20 is the highest open target. During this phase, the strategy behaves like an extreme version of S5, building a massive point advantage before considering any covering.

Phase 2 — Aggressive Covering (Late Game)

When the player has 3 or fewer unclosed targets and 9 or fewer total marks remaining to close them, the strategy permanently switches to S2 behavior (threshold = 0). Cover aggressively and close out as fast as possible. Any point lead at all triggers covering.

The Key Insight

The one-way switch prevents the oscillation that hurts S5 and other high-threshold strategies. Once the player commits to closing, they never go back to scoring. This "locks in" the point advantage built during Phase 1. High-threshold strategies like S5 suffer from repeatedly crossing their threshold in both directions — building a lead, switching to cover, losing the lead due to opponent scoring, switching back to scoring, and so on. Phase Switch eliminates this oscillation by making the transition irreversible.

For a detailed analysis of Phase Switch's performance, grid search optimization, and win rates against every other strategy, see the Phase Switch page.