Our Dig a Garden tier list uses a rigorous four-factor evaluation system. This guide explains exactly how we rank drills so you can understand the reasoning behind each placement. With over 25.7 million visits and a 98.3% approval rating, The Heap's drill simulator has a highly dedicated player base. Because the progression loop—buying drills, placing them on plots, digging items, and selling for Diglets—relies heavily on choosing the right equipment, an objective, transparent ranking methodology is essential. We don't rely on gut feelings; we rely on hard data.
The Four Evaluation Factors
Our ranking system evaluates every drill in Dig a Garden across four distinct categories, each carrying a specific weight that reflects its impact on the core gameplay loop.
1. Diglets Per Hour (35% Weight)
The most important metric — how many Diglets a drill earns per hour of operation. This combines dig speed, item quality distribution, and sell values into a single efficiency number.
Why 35%?: Diglets per hour is the primary goal for most players. Money-making efficiency is the most important factor in drill selection. In a game where upgrading to the next tier of drill can cost hundreds of thousands of Diglets, the rate at which a drill generates raw income dictates your overall progression speed. For example, a high-tier drill like the Mega Borer might generate 45,000 Diglets per hour actively, while the Starter Drill crawls at a fraction of that. This metric ultimately determines how quickly you can expand your garden plot or purchase premium equipment.
2. Legendary Drop Rate (25% Weight)
How likely a drill is to discover legendary-tier items. This measures the rare item discovery probability.
Why 25%?: Legendary items are the most exciting finds in the game and a key goal for many players. The drop rate significantly differentiates drills. While Common items might sell for a handful of Diglets, and Unusual items provide a modest bump, Legendary items can sell for massive amounts, instantly catapulting your earnings. Drills like the Galaxy Drill (currently off-sale but still ranked) skew heavily in this category, offering discovery probabilities that make them vastly superior for collectors and endgame wealth accumulation.
3. Dig Speed (20% Weight)
How quickly a drill discovers items overall. Faster drills find more items per hour, even if individual items may be less valuable.
Why 20%?: Dig speed affects the frequency of all discoveries, not just rare ones. It provides a consistent base income. A drill with a high dig speed but poor rarity rates will still pull up hundreds of Common and Uncommon items, which collectively add up to a substantial income stream. However, dig speed is a double-edged sword; as we will explore in the inventory cap section, drilling too fast without the capacity to hold your items can lead to wasted potential.
4. Value for Cost (20% Weight)
The return on investment — how much you spend vs how much you earn. Free drills score high here, while expensive drills need to justify their cost.
Why 20%?: Cost-effectiveness is important for progression. A drill that costs 100K Diglets needs to earn significantly more than a free alternative. The Group Drill, which is provided for free to members of The Heap group, scores exceptionally well here because its ROI is technically infinite. Conversely, a premium drill must justify its hefty price tag by out-earning the cheaper alternatives at a rate that makes the initial investment worthwhile within a reasonable timeframe.
In-Depth Testing Methodology
To ensure accuracy, our evaluation process follows a strict testing protocol. We do not rely on theoretical maximums provided by the game's tooltips; instead, we conduct real-world testing on standard garden plots.
How We Measure Drill Performance
We test each drill over a 24-hour cycle, split into two phases:
- Active Collection (12 Hours): The player actively collects items from the drill's inventory as soon as it fills. This measures maximum theoretical Diglets per hour.
- Offline Progression (12 Hours): The player leaves the game and returns after 12 hours to measure how the drill performs when limited by inventory caps.
| Testing Parameter | Standard | Rationale |
|---|---|---|
| Test Duration | 24 Hours | Captures a full day-night cycle and varying player activity |
| Plot Size | Standard (Unmodified) | Ensures no plot-specific buffs skew the data |
| Sample Size | 50 Players per Drill | Aggregates community data to eliminate outliers |
| Active Play Window | 12 Hours | Simulates an average active play session |
| Offline Window | 12 Hours | Simulates standard overnight offline progression |
By aggregating data from 50 different players for each drill, we eliminate anomalies caused by luck (such as a player hitting two Legendary items back-to-back) and establish a reliable average for both active and passive play styles.
Drill Category Breakdown & Comparison
Not all tiers are evaluated equally. A C-tier drill is judged on its ability to kickstart your journey, while an S-tier drill is judged on its endgame efficiency. Here is how the criteria shift depending on the drill's category:
| Tier | Drill Examples | Primary Evaluation Focus | Secondary Focus |
|---|---|---|---|
| C | Starter Drill | Value for Cost, Dig Speed | Diglets/Hr |
| B | Standard Borer | Diglets/Hr, Value for Cost | Dig Speed |
| A | Turbo Digger, Deep Piercer, Group Drill | Diglets/Hr, Legendary Drop Rate | Dig Speed |
| S | Mega Borer, Galaxy Drill | Legendary Drop Rate, Diglets/Hr | Value for Cost |
As shown above, Value for Cost is paramount in the early game. The Starter Drill is cheap, so it doesn't need to earn millions to be considered effective. However, for S-tier drills like the Mega Borer, the cost is exorbitant. Therefore, we weight their Legendary Drop Rate and Diglets per hour much more heavily; if an S-tier drill doesn't drastically outclass an A-tier drill in rarity drops, it fails its primary function.
The Inventory Cap Factor
One of the most critical mechanics in Dig a Garden is the inventory cap. When a drill's storage fills up, it stops digging. This means that a drill's raw speed is only as good as your ability to empty its storage.
How Caps Restrict Earnings
If you are an active player who checks your garden every 10 minutes, a fast drill like the Turbo Digger is a massive asset. However, if you primarily rely on offline progression—logging in once every 8 hours—that same Turbo Digger will fill its inventory in 45 minutes and sit idle for the remaining 7 hours and 15 minutes. In this scenario, a slower drill with a larger internal storage capacity might actually earn you more Diglets overnight.
| Drill | Dig Speed | Inventory Cap | Time to Fill | Effective Offline Diglets (8 Hrs) |
|---|---|---|---|---|
| Turbo Digger | Very Fast | 50 Items | ~45 Mins | 12,500 |
| Deep Piercer | Moderate | 120 Items | ~2.5 Hrs | 28,000 |
| Mega Borer | Fast | 200 Items | ~3.5 Hrs | 65,000 |
This table perfectly illustrates why Dig Speed alone cannot dictate our rankings. The Deep Piercer is objectively slower than the Turbo Digger, but its larger inventory cap makes it far more effective for players who rely on offline progression. Our 35% weight on Diglets Per Hour inherently factors in these realistic earning curves, rather than just looking at raw, uninterrupted speed.
How To Choose The Right Drill For You
While our tier list provides a definitive ranking based on aggregate data, your personal playstyle should dictate which drill you actually invest in. Here is a quick walkthrough to help you apply our criteria to your specific situation:
Step 1: Assess Your Playtime
Are you an active grinder or a passive earner?
- Active Players: If you can check your plot frequently, prioritize drills with high Dig Speed and high Legendary Drop rates. You will be emptying the inventory constantly, so caps don't matter. Check out the Turbo Digger if you fall into this category.
- Passive Players: If you log in once or twice a day, prioritize drills with high inventory caps and consistent Diglets per hour over raw speed. The Deep Piercer is ideal here.
Step 2: Calculate Your ROI
Before buying a new drill, calculate how long it will take to pay for itself. If a drill costs 100,000 Diglets and earns 10,000 more Diglets per hour than your current drill, it will take 10 hours of active playtime to see a return on investment. If you only play actively for 1 hour a day, that's a 10-day wait.
Step 3: Upgrade Your Inventory
Before investing in a high-speed drill like the Turbo Digger, ensure you have the inventory capacity to support it. Expanding your plot's storage is often a better use of early Diglets than buying a faster drill that will just sit full. For more on this, see our Inventory Management Guide.
Scoring Example
Below is our base scoring example, which illustrates how the four factors combine for a final ranking score out of 100.
| Drill | Diglets/Hr (35%) | Legendary (25%) | Speed (20%) | Value (20%) | Total |
|---|---|---|---|---|---|
| Galaxy Drill | 35/35 | 25/25 | 18/20 | 12/20 | 90/100 |
| Mega Borer | 33/35 | 15/25 | 18/20 | 18/20 | 84/100 |
| Deep Piercer | 20/35 | 20/25 | 14/20 | 16/20 | 70/100 |
| Starter Drill | 5/35 | 3/25 | 4/20 | 18/20 | 30/100 |
Expanded Scoring Table: The Mid-Tier Overlap
To further clarify how our criteria works, here is an expanded look at the middle-tier drills. These drills often have overlapping scores but serve entirely different purposes:
| Drill | Diglets/Hr (35%) | Legendary (25%) | Speed (20%) | Value (20%) | Total | Best For |
|---|---|---|---|---|---|---|
| Group Drill | 22/35 | 10/25 | 16/20 | 20/20 | 68/100 | F2P Progression |
| Turbo Digger | 24/35 | 12/25 | 20/20 | 10/20 | 66/100 | Active Grinders |
| Standard Borer | 14/35 | 8/25 | 12/20 | 15/20 | 49/100 | Early Game Transition |
Notice how the Group Drill scores a 68, narrowly beating the Turbo Digger's 66. The Turbo Digger is objectively faster and earns more Diglets per hour, but the Group Drill's perfect 20/20 Value score (because it is free via The Heap group) pushes it slightly higher in our overall rankings. However, an active player would still prefer the Turbo Digger, as the Value metric matters less when you are grinding out hundreds of thousands of Diglets. You can view the full breakdown on our Drill Tier List.
FAQ
Q: Why is Diglets per hour weighted more than legendary drop rate? A: Because Diglets earnings fund drill upgrades, which is the core progression loop. Legendary hunting is a secondary goal for most players. Without a steady stream of base Diglets to buy new plots and drills, you cannot even access the content where Legendaries drop.
Q: Does this criteria change? A: The weights may be adjusted based on game updates and community feedback. We review the criteria quarterly. If The Heap introduces a new mechanic that fundamentally shifts how items are sold or stored, we will adjust our weights accordingly and document the changes transparently.
Q: How do you measure Diglets per hour? A: Through community data collection — players track their earnings over multiple sessions and report averages. We aggregate this data for our estimates, filtering out extreme outliers to establish a reliable mean.
Q: What about subjective factors like fun? A: Our ranking is purely based on efficiency metrics. Personal preference is important but outside the scope of this tier list. If you enjoy the animations of the Standard Borer more than the Mega Borer, that is a valid reason to use it, but it won't affect our objective scoring.
Q: How do inventory caps affect your Diglets per hour metric? A: Our Diglets per hour metric accounts for the "effective" Diglets per hour, which includes the downtime caused by full inventories during offline progression. We calculate this based on the average player's check-in frequency, ensuring that drills with tiny inventories aren't artificially inflated in the rankings.
Q: Why is the Group Drill ranked so high despite being free? A: Value for Cost makes up 20% of our total score. Because the Group Drill requires zero financial investment, its return on investment is mathematically infinite. It provides A-tier performance for a C-tier price, making it one of the most efficient drills in the game for early-to-mid progression.
Q: Do you account for offline progression in your testing? A: Yes. Because Dig a Garden features offline progression, a drill's performance while the player is away is just as important as its active performance. Our 24-hour testing cycle specifically includes a 12-hour offline window to capture this data, heavily penalizing drills that fill up too quickly and sit idle overnight.