Prospect Baseline Prospect Baseline
Model Last Run Sep 24, 2026 · 8:41 AM ET

Included in the latest imported public model. All figures reflect the saved assessment dates.

Player profile

Jonathon Long

MIA · AAA · 1B

Miami Marlins · Age at assessment: 24.7 · Bats: R · Throws: R

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Assessment saved: · Stats updated:

Power tool translating

Current game power is broadly aligned with the verified power grade

High Confidence · 99%
PB Rank#351
Prospect Score66
Median59
Performance56
Trend0.0%

Why the player is here

  • Power 50; game-power evidence sits near the 63th percentile for comparable players
  • ISO is 0.172

Context for this assessment, not a verified explanation for movement between model runs.

Tool vs observed results

Percentile scale
Contact+11.1 percentile gap
Expected 58 Observed 69
Game Power+13.2 percentile gap
Expected 50 Observed 63

Verified tool expectations alongside results for comparable players. Percentiles are not scouting grades.

Model history

Median movement
First recorded 49 Latest recorded 59
64 54.5 45 2026-06-04 · Median 49 2026-06-05 · Median 49 2026-06-06 · Median 49 2026-06-07 · Median 49 2026-06-08 · Median 49 2026-06-09 · Median 49 2026-06-10 · Median 50 2026-06-11 · Median 50 2026-06-12 · Median 49 2026-06-13 · Median 50 2026-06-14 · Median 50 2026-06-15 · Median 50 2026-06-16 · Median 50 2026-06-17 · Median 50 2026-06-18 · Median 50 2026-06-19 · Median 51 2026-06-20 · Median 52 2026-06-21 · Median 51 2026-06-22 · Median 52 2026-06-23 · Median 52 2026-06-24 · Median 52 2026-06-25 · Median 53 2026-06-26 · Median 52 2026-06-28 · Median 53 2026-06-29 · Median 53 2026-06-30 · Median 53 2026-07-01 · Median 53 2026-07-03 · Median 56 2026-07-05 · Median 56 2026-07-07 · Median 56 2026-07-09 · Median 56 2026-07-11 · Median 57 2026-07-12 · Median 57 2026-07-14 · Median 57 2026-07-16 · Median 57 2026-07-21 · Median 58 2026-07-22 · Median 58 2026-07-23 · Median 59 2026-07-24 · Median 58 2026-08-20 · Median 59 2026-08-22 · Median 59 2026-08-23 · Median 58.7 2026-08-25 · Median 58.7 2026-08-27 · Median 58 2026-08-28 · Median 58 2026-09-01 · Median 58 2026-09-02 · Median 58 2026-09-03 · Median 58 2026-09-05 · Median 58 2026-09-06 · Median 58 2026-09-09 · Median 60 2026-09-14 · Median 59.7 2026-09-15 · Median 59 2026-09-16 · Median 59 2026-09-17 · Median 59 2026-09-18 · Median 59 2026-09-19 · Median 59 2026-09-21 · Median 59 2026-09-22 · Median 59 2026-09-24 · Median 59 2026-06-04 2026-09-24

2026-09-24 · Median 59

Saved median assessments. Gaps indicate unavailable or non-comparable observations.
View recorded values
DateMedian
2026-09-2459
2026-09-2259
2026-09-2159
2026-09-1959
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2026-09-1459.7
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2026-08-2858
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2026-08-2558.7
2026-08-2358.7
2026-08-2259
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2026-07-2258
2026-07-2158
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2026-06-0649
2026-06-0549
2026-06-0449

Metrics to follow

ISO 0.172

Separates extra-base impact from batting average

Definition

Isolated power, calculated as slugging percentage minus batting average

SLG 0.447

Tracks total bases per at-bat

Definition

Slugging percentage, weighting extra-base hits more heavily

K% 21.6%

Shows the swing-and-miss cost of accessing power

Definition

Percentage of plate appearances ending in a strikeout. Lower is generally better for hitters

Next checkpointRecheck ISO, SLG, and K% after the next 75 plate appearances

2026 season

Current season · regular season
G133
PA598
AVG.275
OBP.369
SLG.447
OPS.816
HR16
SB3
BB%12.5%
K%21.6%

2 teams · Total · All levels · Updated

Scouting Scenario Range

Model Range0.0%
565964
LowMedianHigh
206099
Performance 56

Profile Context

RiskLow Risk · 0
MLB / Model Watch
Confidence93
TypePosition Player

Backtested Forecasts

Separate from scouting grades
2027 MiLB production44.6
Historical 80% error band27–62
MLB arrival in 3 years78%
Productive MLB role in 3 years21%

The next-season score assumes at least 100 PA. A productive MLB role means a regular playing-time season with above-average measured hitting or pitching production. This is not a WAR forecast.

Scouting Tools

Source: Verified public scouting report
Hit icon
Hit55Avg
Power icon
Power50Avg
Speed icon
Speed40Developmental
Defense icon
Defense45Fringe
Arm icon
Arm45Fringe
Overall icon
Overall40Developmental

Tool Profile

Tool ProfileHitPowerSpeedDefenseArm20-80 grade scaleArchetype: Balanced Position Player

Player Stats

Recent regular season
PeriodTeamLevelGPAABRH2B3BHRRBIBBSOSBAVGOBPSLGOPS
Last 7 daysAll teamsAll levels154021002000.500.400.7501.150
Last 30 daysAll teamsAll levels18796610164031410160.242.329.439.769
Year-by-year regular season
YearTeamLevelGPAABRH2B3BHRRBIBBSOSBAVGOBPSLGOPS
2026Iowa CubsAAA9945239667112301126248962.283.364.455.818
2026Jacksonville Jumbo ShrimpAAA3414611626296142127331.250.384.422.806
20262 teams · TotalAll levels133598512931413621683751293.275.369.447.816
2025Iowa CubsAAA140607514861572332091791162.305.404.479.883
2024Tennessee SmokiesAA4620015942549072935330.340.455.528.983
2024South Bend CubsHigh-A682892474461120104134682.247.346.417.763
20242 teams · TotalAll levels114489406861152101770691012.283.391.461.851
2023Myrtle Beach PelicansSingle-A23927711203061211180.260.380.532.913
2023ACL CubsACL3107231012300.429.6001.0001.600
20232 teams · TotalAll levels261028413234071414180.274.402.571.973

Regular season only. Totals combine team and level stints. Recent windows overlap and use cached game logs. Stats refreshed: 2026-09-24T08:35:32.

More Miami Marlins profiles

Organization reflects each player's saved assessment.